1 00:00:06,173 --> 00:00:08,707 Narrator: Where emperors reign. 2 00:00:08,809 --> 00:00:12,360 And gladiators entertain. 3 00:00:12,847 --> 00:00:18,467 Site of luxury, excess and the ever-present danger of the mob. 4 00:00:20,271 --> 00:00:24,707 For five centuries, rome dominates the western world, 5 00:00:24,809 --> 00:00:28,977 But the real secret of the empire's power lies elsewhere, 6 00:00:29,080 --> 00:00:32,047 Beneath the seas it once commanded. 7 00:00:32,917 --> 00:00:34,867 Jon: Without the sea and without controlling the trade 8 00:00:34,969 --> 00:00:38,303 Routes of the sea, there would have been no empire. 9 00:00:39,473 --> 00:00:42,007 Narrator: Imagine if we could empty the oceans, 10 00:00:42,109 --> 00:00:44,009 Letting the water drain away, 11 00:00:44,111 --> 00:00:46,979 To reveal the secrets of the seafloor. 12 00:00:50,568 --> 00:00:53,969 Now, we can. 13 00:00:54,572 --> 00:00:57,740 Using accurate data and astonishing technology to 14 00:00:57,842 --> 00:01:01,443 Bring light once again to a lost world. 15 00:01:06,183 --> 00:01:08,867 This time, how does a mysterious lake, 16 00:01:08,969 --> 00:01:10,569 Miles from the city, 17 00:01:10,671 --> 00:01:13,672 Explain rome's mastery of the mediterranean. 18 00:01:14,942 --> 00:01:17,910 Peter: It was built on a scale unlike anything else, 19 00:01:18,012 --> 00:01:21,180 Only the roman emperors were this ambitious. 20 00:01:21,966 --> 00:01:24,366 Narrator: What can a maritime graveyard unearthed in an 21 00:01:24,468 --> 00:01:28,604 Italian field tell us of rome's one great weakness? 22 00:01:30,875 --> 00:01:34,576 And how does a lost marvel on a distant mediterranean shore 23 00:01:34,678 --> 00:01:38,814 Explain rome's greatest ever feat of engineering. 24 00:01:39,884 --> 00:01:43,135 Beverly: The romans took technology to a whole 'nother level. 25 00:01:44,071 --> 00:01:48,907 (theme music plays), 26 00:01:57,735 --> 00:02:00,068 Narrator: When the great historian, livy, 27 00:02:00,237 --> 00:02:03,238 Sets out to write the story of his city, 28 00:02:05,876 --> 00:02:09,678 He knows it all comes down to location. 29 00:02:13,184 --> 00:02:16,335 Livy: Gods and men together chose this place. 30 00:02:17,471 --> 00:02:20,405 Hills with pure air. 31 00:02:21,942 --> 00:02:24,443 A convenient river. 32 00:02:24,545 --> 00:02:27,880 A sea, handy for our needs. 33 00:02:27,982 --> 00:02:33,001 All these advantages marked us out for glory. 34 00:02:35,773 --> 00:02:39,107 Narrator: Rome is the world's first superpower, 35 00:02:39,210 --> 00:02:42,110 But it doesn't start that way. 36 00:02:44,682 --> 00:02:47,466 Over the course of 500 years, 37 00:02:47,568 --> 00:02:50,335 It grows from a fortified settlement 38 00:02:50,437 --> 00:02:52,938 To a powerful republic and finally, 39 00:02:53,040 --> 00:02:55,107 An empire. 40 00:02:55,576 --> 00:02:59,011 Demanding the allegiance of over 16 million people, 41 00:02:59,113 --> 00:03:02,281 From britain in the north, down the coast of africa 42 00:03:02,383 --> 00:03:05,234 And into the middle east. 43 00:03:07,004 --> 00:03:11,306 Rome's power rests on the unrivalled might of its army. 44 00:03:12,943 --> 00:03:16,712 And engineering skills that astonish its rivals. 45 00:03:17,248 --> 00:03:19,248 But that's not all. 46 00:03:19,350 --> 00:03:20,899 Jon: So everyone thinks they know the story of the 47 00:03:21,001 --> 00:03:24,369 Roman empire, it's a story of legions and of roads and 48 00:03:24,471 --> 00:03:27,239 Of building massive structures. 49 00:03:27,341 --> 00:03:30,209 But the key really was control of the sea. 50 00:03:32,446 --> 00:03:35,180 Narrator: Controlling the seas is essential, 51 00:03:35,282 --> 00:03:38,400 Because rome struggles to feed its people. 52 00:03:39,336 --> 00:03:42,971 By the first century ad, the population of the capital 53 00:03:43,073 --> 00:03:45,841 Swells to one million. 54 00:03:46,844 --> 00:03:49,845 The largest city the world has ever seen. 55 00:03:54,368 --> 00:03:59,438 And if those people go hungry, they riot. 56 00:04:02,276 --> 00:04:03,976 Jon: What rome is dependent on, 57 00:04:04,078 --> 00:04:08,413 Obtaining about 150 to 300 million tons of grain annually 58 00:04:08,515 --> 00:04:12,467 To keep the population fed, if you were an emperor, 59 00:04:12,569 --> 00:04:14,503 You wanted to be seen as someone who was providing 60 00:04:14,605 --> 00:04:16,305 For the population. 61 00:04:16,407 --> 00:04:18,240 So really, without that grain coming in, 62 00:04:18,342 --> 00:04:20,142 They couldn't hold on to power. 63 00:04:20,244 --> 00:04:24,179 Narrator: How the emperors managed this has long puzzled historians. 64 00:04:25,950 --> 00:04:30,235 But now, buried underground and miles inland, 65 00:04:30,337 --> 00:04:34,640 An extraordinary discovery could unlock the mystery. 66 00:04:37,511 --> 00:04:41,580 Rome's challenge isn't shipping grain from the empire. 67 00:04:42,750 --> 00:04:46,168 It's getting it to the city itself. 68 00:04:48,439 --> 00:04:51,707 15 miles from the sea. 69 00:04:53,177 --> 00:04:56,144 There must have been a huge port somewhere on the coast, 70 00:04:56,246 --> 00:04:59,014 Or inland, up the river tiber. 71 00:05:00,284 --> 00:05:03,735 But its whereabouts are a mystery. 72 00:05:09,143 --> 00:05:11,843 Today, international teams are trying to piece together the 73 00:05:11,945 --> 00:05:14,479 Puzzle of the lost port. 74 00:05:16,250 --> 00:05:19,001 Archaeologist, peter campbell, is determined to discovery how 75 00:05:19,103 --> 00:05:22,337 Rome handled its biggest problem. 76 00:05:22,439 --> 00:05:24,339 Peter: Feeding nearly a million people would have 77 00:05:24,441 --> 00:05:26,408 Been an incredible task. 78 00:05:26,510 --> 00:05:28,844 The ability to get that material from around the 79 00:05:28,946 --> 00:05:32,481 Mediterranean up to the city took just an incredible amount 80 00:05:32,583 --> 00:05:35,400 Of human willpower and labor. 81 00:05:39,373 --> 00:05:41,106 Simon: You need anchorage space, 82 00:05:41,208 --> 00:05:43,942 You need harbor facilities. 83 00:05:44,545 --> 00:05:46,278 Narrator: Simon kay leads a group of experts 84 00:05:46,380 --> 00:05:49,648 Who are studying the lost port. 85 00:05:50,467 --> 00:05:52,267 Simon: You need the infrastructure to support them 86 00:05:52,336 --> 00:05:55,103 And you need the administrative framework 87 00:05:55,205 --> 00:05:58,440 Indeed, to enable them to function. 88 00:06:00,544 --> 00:06:03,211 Narrator: Clues, first unearthed over a century ago, 89 00:06:03,313 --> 00:06:04,913 Are tantalizing. 90 00:06:05,015 --> 00:06:07,933 Simon: The early sources are very very important. 91 00:06:08,035 --> 00:06:11,703 They saw things, they recorded them. 92 00:06:12,973 --> 00:06:17,409 Narrator: Historical texts refer to a port without equal. 93 00:06:18,045 --> 00:06:21,580 Somewhere on the coast, near the mouth of the tiber. 94 00:06:23,016 --> 00:06:27,102 Established by the emperor claudius by 46 ad. 95 00:06:27,204 --> 00:06:31,940 And extended by the emperor trajan, over 60 years later. 96 00:06:35,846 --> 00:06:39,181 The romans call it portus. 97 00:06:39,283 --> 00:06:41,032 A single carved relief, 98 00:06:41,135 --> 00:06:43,635 Dating from the late second century ad 99 00:06:43,737 --> 00:06:46,905 Hints at its magnificence. 100 00:06:47,808 --> 00:06:52,444 But gives no sense of its true scale, or how it worked. 101 00:06:56,450 --> 00:07:00,135 Other sources speak of a hexagonal basin at the center 102 00:07:00,304 --> 00:07:04,539 Of a vast complex, called the portus traiani. 103 00:07:05,909 --> 00:07:10,378 Could evidence of it still survive, 2,000 years later? 104 00:07:15,836 --> 00:07:18,804 Simon is convinced that it does, 105 00:07:18,906 --> 00:07:22,441 About 15 miles south of rome, where he's come to investigate 106 00:07:22,543 --> 00:07:26,411 Strange ruins and a mysterious lake. 107 00:07:27,881 --> 00:07:32,667 It has six clearly defined sites and looks manmade. 108 00:07:34,538 --> 00:07:37,005 It covers almost 80 acres, 109 00:07:37,107 --> 00:07:41,176 As large as 13 roman coliseums joined together. 110 00:07:42,079 --> 00:07:44,279 But there's a problem. 111 00:07:44,381 --> 00:07:48,433 It's two miles from the mediterranean coast. 112 00:07:48,535 --> 00:07:53,605 Could the heart of the legendary portus lie so far in land. 113 00:07:55,042 --> 00:07:57,509 And where is the rest of it? 114 00:07:57,611 --> 00:08:00,745 Simon: So little is known about the layout of the ancient port. 115 00:08:00,914 --> 00:08:05,500 It's very, very hard to understand how it all fits together. 116 00:08:10,240 --> 00:08:13,542 Narrator: Archaeologists survey close to the lake. 117 00:08:13,644 --> 00:08:15,377 Man: Through here, then you just get in the different 118 00:08:15,479 --> 00:08:18,079 Phases, running down through there. 119 00:08:18,782 --> 00:08:22,300 Narrator: Probing beneath the surface for any evidence. 120 00:08:25,973 --> 00:08:30,175 Man: About a meter, a meter and a half or so, 121 00:08:30,277 --> 00:08:33,778 Four meters you start hitting the water table. 122 00:08:35,649 --> 00:08:37,732 Narrator: Combining discoveries made here during 123 00:08:37,834 --> 00:08:40,902 Past construction work. 124 00:08:42,272 --> 00:08:45,907 And these new archaeological investigations. 125 00:08:47,744 --> 00:08:52,380 It's now possible to produce a new window into the past. 126 00:08:55,502 --> 00:09:00,438 The mud and silt of 2,000 years drains away. 127 00:09:02,576 --> 00:09:05,210 And six feet below the surface, 128 00:09:05,312 --> 00:09:08,513 Buried archaeological treasure. 129 00:09:10,517 --> 00:09:13,868 The remains, not of a port. 130 00:09:15,739 --> 00:09:18,740 But something that might have used it. 131 00:09:20,277 --> 00:09:22,210 A boat. 132 00:09:22,312 --> 00:09:25,614 From this field, two miles from the coast, 133 00:09:25,716 --> 00:09:29,234 Four other vessels emerge into the light. 134 00:09:30,704 --> 00:09:34,205 It's an extraordinary discovery. 135 00:09:39,212 --> 00:09:42,681 The archaeologists pour over the evidence. 136 00:09:42,783 --> 00:09:46,701 And realize they are some of the most complete 137 00:09:46,803 --> 00:09:49,971 Roman vessels ever discovered. 138 00:09:50,073 --> 00:09:53,675 It's even possible to date one of them. 139 00:09:54,344 --> 00:09:56,011 Peter: Based on the construction features, 140 00:09:56,113 --> 00:09:58,947 We can estimate that it dates to the second century ad. 141 00:10:00,117 --> 00:10:02,200 Narrator: In the second century, 142 00:10:02,302 --> 00:10:05,170 The roman empire is at its height. 143 00:10:05,272 --> 00:10:08,940 If it ever needed a truly grand port, 144 00:10:09,042 --> 00:10:11,343 This is the moment. 145 00:10:13,213 --> 00:10:16,948 But if these beautifully preserved boats used this port, 146 00:10:17,050 --> 00:10:20,568 Why are they so far inland? 147 00:10:23,573 --> 00:10:25,974 Peter campbell finds more evidence. 148 00:10:28,111 --> 00:10:30,178 Not far from the wooden boats, 149 00:10:30,280 --> 00:10:34,265 The remains of what looks like a long, low wall. 150 00:10:36,069 --> 00:10:39,437 And it's definitely roman. 151 00:10:46,513 --> 00:10:50,315 More surveys reveal this is just one section of an early 152 00:10:50,417 --> 00:10:52,901 6,000 foot long structure. 153 00:10:53,003 --> 00:10:56,938 Now, mostly hidden beneath the ground. 154 00:10:58,642 --> 00:11:02,344 Further archaeological work unearths a second wall, 155 00:11:02,446 --> 00:11:05,313 Curling back towards the first. 156 00:11:07,834 --> 00:11:11,102 And deposits on the walls give a further clue. 157 00:11:13,607 --> 00:11:15,106 Peter: If you walk along the structure, 158 00:11:15,208 --> 00:11:17,642 You can actually see calcium deposits at a certain level 159 00:11:17,744 --> 00:11:20,078 And it creates this white line along the length of it and 160 00:11:20,180 --> 00:11:22,814 Those are actually marine concretions. 161 00:11:23,884 --> 00:11:26,568 Narrator: Marine concretions are sediments that cling to 162 00:11:26,670 --> 00:11:30,905 Structures at seawater level, leaving a white mark. 163 00:11:32,909 --> 00:11:36,144 This whole area, close to the hexagonal basin, 164 00:11:36,246 --> 00:11:39,414 Was once under water. 165 00:11:41,735 --> 00:11:44,936 It's another astonishing find. 166 00:11:50,310 --> 00:11:53,578 In roman days, this is where the coast was. 167 00:11:54,481 --> 00:11:58,533 And the curving structures make up a huge protective harbor. 168 00:12:00,070 --> 00:12:02,704 This must be portus. 169 00:12:05,842 --> 00:12:08,476 But one big question remains. 170 00:12:10,781 --> 00:12:14,999 The city is 15 miles further inland. 171 00:12:16,570 --> 00:12:21,473 Connected to the sea by the river tiber and the mouth of 172 00:12:21,575 --> 00:12:25,310 The river is nearly two miles from portus. 173 00:12:26,446 --> 00:12:29,581 So how did food ever get to rome? 174 00:12:39,743 --> 00:12:43,178 Narrator: The architects who designed portus faced one key 175 00:12:43,280 --> 00:12:47,015 Challenge, feeding rome's million strong population. 176 00:12:49,002 --> 00:12:53,338 So how does the harbor connect to the city, 15 miles away? 177 00:12:54,875 --> 00:12:57,675 Moving huge volumes of cargo by existing roads 178 00:12:57,778 --> 00:13:01,446 Would have been costly. 179 00:13:02,916 --> 00:13:05,667 And the most obvious route to rome, the river tiber, 180 00:13:05,786 --> 00:13:09,237 Is too shallow for merchant vessels. 181 00:13:13,910 --> 00:13:18,313 Studying the ancient boats dug up nearby, 182 00:13:18,415 --> 00:13:23,001 Peter campbell finds an important clue. 183 00:13:25,772 --> 00:13:27,605 Peter: Rather than having a v shape, 184 00:13:27,707 --> 00:13:29,274 As you would have with a seagoing ship, 185 00:13:29,376 --> 00:13:31,309 This actually has a relatively flat bottom, 186 00:13:31,411 --> 00:13:34,179 Which would have allowed it to travel in much shallower waters. 187 00:13:34,614 --> 00:13:37,599 It was used within the harbor and up the tiber. 188 00:13:38,635 --> 00:13:40,668 This vessel's an important piece of the puzzle in the 189 00:13:40,770 --> 00:13:44,205 Network that connected the ocean to the city. 190 00:13:46,610 --> 00:13:50,211 Narrator: The harbor lies more than a mile from the banks of the tiber. 191 00:13:52,249 --> 00:13:56,401 How could a cargo carrying vessel reach the river? 192 00:13:57,804 --> 00:14:01,506 Peter consults the archaeological surveys. 193 00:14:01,608 --> 00:14:05,844 And spots a set of parallel lines near the hexagonal basin. 194 00:14:08,048 --> 00:14:12,066 They look like the remains of a manmade channel. 195 00:14:13,537 --> 00:14:17,505 The data reveals a major canal system connected 196 00:14:17,607 --> 00:14:22,076 Portus harbor to the tiber. 197 00:14:23,847 --> 00:14:27,699 An astonishing feat of roman engineering. 198 00:14:29,870 --> 00:14:33,671 Peter: If you look at the landscape of the river today, 199 00:14:33,773 --> 00:14:36,207 There's the main channel that we're in right now. 200 00:14:36,309 --> 00:14:38,243 But in the past, there would have been multiple other 201 00:14:38,345 --> 00:14:41,246 Canals, and we've only recently discovered those 202 00:14:41,348 --> 00:14:44,082 Others through geoarchaeology. 203 00:14:46,403 --> 00:14:49,203 Narrator: The archaeologists now understand the full scale 204 00:14:49,306 --> 00:14:52,874 Of the portus complex and how it connects to rome. 205 00:14:55,011 --> 00:14:57,946 But there is still a mystery. 206 00:14:58,048 --> 00:15:01,733 At the heart of the port, beyond the vast main harbor, 207 00:15:01,835 --> 00:15:05,603 Lies the huge enclosed hexagonal basin. 208 00:15:06,306 --> 00:15:10,475 Apparently, unique in the ancient world. 209 00:15:10,577 --> 00:15:13,411 But what was it for? 210 00:15:14,414 --> 00:15:18,633 Today, from the surface, it seems like an ordinary lake. 211 00:15:19,603 --> 00:15:22,070 But by using the latest computer visualization 212 00:15:22,172 --> 00:15:26,908 Techniques, we can look deeper. 213 00:15:31,214 --> 00:15:34,632 As the water seeps away, it exposes, 214 00:15:34,734 --> 00:15:37,402 Not the muddy banks of a natural lake, 215 00:15:37,504 --> 00:15:40,371 But a crumbling brick wall. 216 00:15:41,841 --> 00:15:46,110 Similar walls support the other sides of the hexagon 217 00:15:46,212 --> 00:15:49,781 And then something startling. 218 00:15:50,884 --> 00:15:54,736 A white block, with a hole through the center. 219 00:15:55,171 --> 00:15:58,873 One of dozens protruding from the brickwork. 220 00:15:58,975 --> 00:16:03,645 Close by, the remains of a column. 221 00:16:05,248 --> 00:16:10,468 And just visible on it, roman symbols for the number 23. 222 00:16:17,477 --> 00:16:22,313 Can ruins scattered nearby help reveal the hexagon's purpose? 223 00:16:24,150 --> 00:16:26,734 Simon keay thinks so. 224 00:16:29,039 --> 00:16:33,875 To his expert eye, they are roman and important. 225 00:16:36,413 --> 00:16:38,046 Simon: I'm currently standing on one of the largest 226 00:16:38,148 --> 00:16:41,265 Surviving buildings from portus. 227 00:16:41,334 --> 00:16:44,435 Narrator: The thick walls, large enclosed space and a 228 00:16:44,537 --> 00:16:48,306 Wide opening all point to one thing. 229 00:16:49,509 --> 00:16:52,477 These are warehouses. 230 00:16:52,579 --> 00:16:55,446 Warehouses designed to store the most important commodity 231 00:16:55,548 --> 00:16:59,634 In the roman empire, grain for the people of rome. 232 00:17:00,637 --> 00:17:03,771 Simon: They are the largest place of grain storage in the 233 00:17:03,873 --> 00:17:07,809 Whole portus complex, making them the largest 234 00:17:07,911 --> 00:17:11,079 Grain warehouses in the roman empire. 235 00:17:14,901 --> 00:17:19,370 Narrator: It's now clear what the drained hexagonal lake is for. 236 00:17:22,609 --> 00:17:25,443 Mooring rings for ships to unload, 237 00:17:25,545 --> 00:17:27,745 A broad quayside surrounding the lake. 238 00:17:30,750 --> 00:17:33,334 And the numbered column docking station, 239 00:17:33,436 --> 00:17:36,537 One of dozens in the whole complex. 240 00:17:37,273 --> 00:17:41,242 The hexagon is the heart of portus. 241 00:17:42,812 --> 00:17:47,448 A purpose built facility to manage dozens of cargo ships at a time. 242 00:17:50,603 --> 00:17:52,937 Decades of archaeological work haven't simply found some 243 00:17:53,039 --> 00:17:56,541 Ancient docks and warehouse. 244 00:17:56,626 --> 00:18:00,611 They've uncovered the secret to the success of rome itself, 245 00:18:00,780 --> 00:18:04,182 Allowing us to understand exactly how the emperors 246 00:18:04,284 --> 00:18:06,901 Fed a million people. 247 00:18:09,706 --> 00:18:13,374 Now, for the first time in almost two millennia, 248 00:18:13,476 --> 00:18:17,712 The true scale and brilliance of portus is revealed in full. 249 00:18:21,901 --> 00:18:25,403 Approaching ships arrive at the outer harbor. 250 00:18:25,505 --> 00:18:29,107 Some moor here. 251 00:18:30,343 --> 00:18:33,811 Others head further into the port. 252 00:18:34,447 --> 00:18:38,666 To dock at numbered mooring rings. 253 00:18:43,873 --> 00:18:48,509 The great basin can hold over 100 vessels. 254 00:18:51,447 --> 00:18:55,766 Surrounding them, another engineering marvel and a hint 255 00:18:55,869 --> 00:18:59,137 Of the majesty of rome. 256 00:19:01,374 --> 00:19:04,742 Not only warehouses and harbor offices, 257 00:19:04,844 --> 00:19:08,045 But giant temples and statues too. 258 00:19:10,650 --> 00:19:13,668 The sheer volume of goods passing through portus is 259 00:19:13,770 --> 00:19:17,305 Beyond anything the world has ever seen. 260 00:19:19,108 --> 00:19:22,844 While a host of smaller barges wait to ferry cargo through 261 00:19:22,946 --> 00:19:27,181 The canals, to the river tiber and onto rome. 262 00:19:29,769 --> 00:19:33,604 The hexagonal basin at portus is the final crucial link in 263 00:19:33,706 --> 00:19:37,909 The supply chain from the empire to rome itself. 264 00:19:41,981 --> 00:19:46,434 The ultimate symbol of rome's mastery of the seas. 265 00:19:48,171 --> 00:19:50,638 Jon: In portus, we're seeing the roman empire at its height, 266 00:19:50,740 --> 00:19:52,673 We're seeing the first and second centuries ad, 267 00:19:52,775 --> 00:19:54,609 They're building a massive port. 268 00:19:54,711 --> 00:19:57,378 And it's the most advanced, it's the most monumental, 269 00:19:57,480 --> 00:19:59,647 It's the most spectacular port and it's actually making a 270 00:19:59,749 --> 00:20:01,799 Statement about rome. 271 00:20:03,803 --> 00:20:06,637 Narrator: Vessels from across the empire flock 272 00:20:06,739 --> 00:20:09,607 To this engineering marvel. 273 00:20:09,709 --> 00:20:14,412 Can the surprising cargo of one ship destined for portus 274 00:20:14,514 --> 00:20:19,533 Explain how rome survives one of its greatest ever disasters? 275 00:20:30,079 --> 00:20:31,646 Narrator: The mediterranean, 276 00:20:31,748 --> 00:20:34,448 Superhighway of the roman empire. 277 00:20:35,535 --> 00:20:38,536 For five centuries, it's crisscrossed by merchant 278 00:20:38,638 --> 00:20:42,540 Ships, many carrying grain to portus. 279 00:20:45,311 --> 00:20:48,379 Very few have ever been found. 280 00:20:50,917 --> 00:20:54,468 But off the coast of Spain, near the city of alicante, 281 00:20:54,570 --> 00:20:57,171 An ancient shipwreck is discovered by two amateur 282 00:20:57,273 --> 00:21:01,676 Divers, jose bou and antoine ferrer. 283 00:21:04,380 --> 00:21:09,500 Maritime archaeologists name it after them, the bou ferrer. 284 00:21:12,472 --> 00:21:14,905 When carols de juan hears about it, 285 00:21:15,008 --> 00:21:17,775 He sets out to discover more. 286 00:21:24,484 --> 00:21:25,566 Carlos: We have seen everything, 287 00:21:25,668 --> 00:21:27,501 So a sea break from roman period, 288 00:21:27,603 --> 00:21:31,672 Right underneath where we are right now. 289 00:21:32,842 --> 00:21:35,543 It is absolutely emotional. 290 00:21:35,645 --> 00:21:37,712 Emotional moment. 291 00:21:39,048 --> 00:21:42,333 And I felt that it was the beginning of something. 292 00:21:51,411 --> 00:21:53,678 Narrator: 80 feet below the surface, 293 00:21:53,780 --> 00:21:56,847 Something rare and precious. 294 00:21:58,301 --> 00:22:03,104 The bones of the bou ferrer and the remains of her cargo. 295 00:22:04,907 --> 00:22:08,476 Carlos thinks its roman, but is he right? 296 00:22:10,113 --> 00:22:13,180 And what was she carrying? 297 00:22:20,340 --> 00:22:23,841 The mediterranean empties. 298 00:22:25,978 --> 00:22:29,180 And light pours once again onto this ancient and 299 00:22:29,282 --> 00:22:32,233 Mysterious ship. 300 00:22:33,936 --> 00:22:38,105 Spread across the seafloor, a mountain of amphorae, 301 00:22:38,241 --> 00:22:41,208 Many completely intact, despite lying at the bottom of 302 00:22:41,310 --> 00:22:44,845 The mediterranean for many centuries. 303 00:22:47,784 --> 00:22:51,168 The storage jars are used to carry food, 304 00:22:51,270 --> 00:22:53,504 Oil and wine in the ancient world. 305 00:22:56,509 --> 00:22:59,944 Clear evidence that this is a roman wreck. 306 00:23:03,816 --> 00:23:07,501 The sheer number of amphorae suggests she was an unusually 307 00:23:07,603 --> 00:23:12,440 Large cargo ship, but little of her frame remains. 308 00:23:13,876 --> 00:23:18,712 Just a few timbers from the hull have survived the ravages of time. 309 00:23:22,301 --> 00:23:24,168 Carlos: It is a great opportunity for the 310 00:23:24,270 --> 00:23:28,672 Archaeology to learn more about those big vessels, 311 00:23:28,775 --> 00:23:31,909 Those merchant vessels of roman period. 312 00:23:35,248 --> 00:23:38,899 Narrator: The fully drained remains reveal a shape that's 313 00:23:39,001 --> 00:23:42,136 Typical of a roman merchant ship, 314 00:23:42,238 --> 00:23:44,905 But much bigger than most. 315 00:23:49,645 --> 00:23:52,746 Pulling her skeleton together from the bottom of the sea, 316 00:23:52,849 --> 00:23:55,566 We can recreate the bou ferrer as she was 317 00:23:55,668 --> 00:23:58,269 On the day she sank. 318 00:24:01,808 --> 00:24:04,842 30 feet wide and almost 100 feet long, 319 00:24:04,944 --> 00:24:07,878 She's larger than a tennis court. 320 00:24:11,217 --> 00:24:15,669 Capable of carrying over 200 tons of cargo. 321 00:24:21,511 --> 00:24:23,344 Carlos: We have other questions, 322 00:24:23,446 --> 00:24:27,982 So we have to investigate inside of the shipwreck. 323 00:24:31,904 --> 00:24:34,538 Narrator: So little remains of the ship. 324 00:24:36,142 --> 00:24:39,543 Carlos must look to the cargo, to learn more. 325 00:24:43,382 --> 00:24:46,767 The team raise some of the jars to the surface. 326 00:24:56,245 --> 00:25:00,614 Each weighs nearly 140 pounds. 327 00:25:07,039 --> 00:25:10,941 On land, they're handled delicately and examined 328 00:25:11,043 --> 00:25:14,211 In minute detail. 329 00:25:25,741 --> 00:25:27,608 Carlos: We have set to discover some pottery 330 00:25:27,710 --> 00:25:32,079 Fragments that have a waterproof resin inside. 331 00:25:34,250 --> 00:25:37,434 Narrator: Waterproof resin is a key clue. 332 00:25:37,537 --> 00:25:41,305 It means the amphorae carried liquid. 333 00:25:41,407 --> 00:25:45,943 And in some of them, ancient sediment from that liquid 334 00:25:46,045 --> 00:25:49,446 Reveals something else. 335 00:25:50,383 --> 00:25:53,234 Fish bones. 336 00:25:53,736 --> 00:25:56,503 The amphorae carry one of the most popular products of the 337 00:25:56,606 --> 00:26:00,574 Roman economy, the super food of the ancient world. 338 00:26:02,878 --> 00:26:07,181 Fish sauce, known as garum. 339 00:26:08,401 --> 00:26:10,601 Jon: Well, garum, or fish sauce is basically a condiment 340 00:26:10,703 --> 00:26:13,137 That you would add to food to enhance its flavor, 341 00:26:13,239 --> 00:26:14,872 As you would today, as you would do with soy sauce, 342 00:26:14,974 --> 00:26:16,807 Or something like that. 343 00:26:18,177 --> 00:26:21,812 And that's because roman food really was a bit bland. 344 00:26:21,914 --> 00:26:23,948 Narrator: And this is before they had tomatoes, 345 00:26:24,050 --> 00:26:25,799 Before they had pizza, before they had, you know, 346 00:26:25,901 --> 00:26:28,669 The things we think of in terms of italian food. 347 00:26:30,139 --> 00:26:33,941 So the bou ferrer was carrying fish sauce. 348 00:26:34,043 --> 00:26:37,111 But where had it come from? 349 00:26:39,882 --> 00:26:43,801 The shape of the amphorae gives carlos a clue. 350 00:26:45,204 --> 00:26:49,607 Carlos: We knew that that kind of amphoras are related 351 00:26:49,709 --> 00:26:53,143 To the fisheries from the south of Spain. 352 00:26:57,249 --> 00:27:01,035 Narrator: But where was the bou ferrer taking them? 353 00:27:02,772 --> 00:27:07,007 Returning to the drained wreck and removing layers of the 354 00:27:07,109 --> 00:27:11,111 Amphorae reveals further evidence. 355 00:27:12,948 --> 00:27:17,101 A secret cargo hidden for centuries. 356 00:27:18,571 --> 00:27:23,173 On either side of the keel, strange metal ingots. 357 00:27:32,668 --> 00:27:36,637 The team prizes 22 of them from the wreck. 358 00:27:46,649 --> 00:27:50,567 Each weighs 140 pounds. 359 00:28:00,479 --> 00:28:03,647 In the laboratory, careful examination of the ingots 360 00:28:03,749 --> 00:28:07,234 Reveals something unexpected. 361 00:28:08,671 --> 00:28:13,674 The hidden cargo is not gold, or silver, it's lead. 362 00:28:16,612 --> 00:28:19,613 And there's something else. 363 00:28:21,150 --> 00:28:27,137 All the ingots found on bou ferrer are stamped with the letters, imp. 364 00:28:31,177 --> 00:28:33,944 It's the mark of the imperator, 365 00:28:34,046 --> 00:28:37,247 The latin word for emperor. 366 00:28:38,667 --> 00:28:43,203 Carlos: Those marks are telling us that this ingots 367 00:28:43,305 --> 00:28:47,141 Belongs to the emperor and that was like, "wow." 368 00:28:49,545 --> 00:28:52,780 That was just the moment where the bou ferrer 369 00:28:52,882 --> 00:28:56,967 Changed from such a large big roman vessel, 370 00:28:57,069 --> 00:28:59,937 To something absolutely different. 371 00:29:00,973 --> 00:29:04,808 A vessel that has been able to link in the story of rome. 372 00:29:04,910 --> 00:29:08,045 Narrator: The bou ferrer isn't just another cargo ship. 373 00:29:08,147 --> 00:29:11,431 It's taking at least a ton of metal to the most powerful man 374 00:29:11,517 --> 00:29:14,101 In the world. 375 00:29:14,203 --> 00:29:18,005 So which emperor could it be destined for and why does he 376 00:29:18,107 --> 00:29:21,041 Need a boatload of lead? 377 00:29:32,738 --> 00:29:34,238 Narrator: Off the coast of Spain, 378 00:29:34,340 --> 00:29:37,941 A remarkable roman shipwreck, called the bou ferrer, 379 00:29:38,043 --> 00:29:40,744 Conceals a secret cargo. 380 00:29:41,847 --> 00:29:43,647 A fortune in lead, 381 00:29:43,749 --> 00:29:47,434 Possibly destined for the emperor of rome himself. 382 00:29:50,906 --> 00:29:56,009 The drained wreck holds clues that could reveal which emperor. 383 00:29:57,646 --> 00:30:02,099 Hidden amongst the amphorae are two weathered coins. 384 00:30:13,579 --> 00:30:17,581 The coins are made of bronze. 385 00:30:18,567 --> 00:30:22,169 On one side, a faint image. 386 00:30:22,271 --> 00:30:25,906 Almost invisible marks prove the coins were stamped around 387 00:30:26,008 --> 00:30:31,578 Ad 66, during the reign of one of the most infamous 388 00:30:31,680 --> 00:30:34,615 Emperors of them all. 389 00:30:37,236 --> 00:30:39,636 Nero. 390 00:30:43,108 --> 00:30:47,010 The information from the coins allows carlos to do something 391 00:30:47,112 --> 00:30:50,030 Even more remarkable. 392 00:30:51,617 --> 00:30:55,702 Date the sinking of the bou ferrer to the time of one of 393 00:30:55,804 --> 00:30:59,439 Rome's greatest disasters. 394 00:31:02,344 --> 00:31:07,381 In 64 ad, an inferno ravages the city for six days. 395 00:31:09,268 --> 00:31:12,569 According to legend, nero plays his fiddle, 396 00:31:12,671 --> 00:31:15,706 While his capital burns. 397 00:31:17,142 --> 00:31:20,010 Whether that's true or not, the huge damage gives him the 398 00:31:20,112 --> 00:31:24,081 Chance to rebuild the city in his own image. 399 00:31:24,383 --> 00:31:26,633 Jon: The great fire of rome destroyed about two thirds of 400 00:31:26,735 --> 00:31:29,436 The city and there was a massive rebuilding campaign 401 00:31:29,538 --> 00:31:31,338 In the years that followed and they obviously, 402 00:31:31,440 --> 00:31:33,206 Needed the raw materials to do that. 403 00:31:33,309 --> 00:31:35,642 Lead was a very important part of that. 404 00:31:36,979 --> 00:31:41,181 Narrator: Lead lines pipes, in all kinds of roman plumbing. 405 00:31:41,283 --> 00:31:45,469 Like the luxurious bathhouses enjoyed by the wealthy elite. 406 00:31:47,840 --> 00:31:51,308 Carlos believes the emperor's mark is evidence that this 407 00:31:51,410 --> 00:31:55,212 Cargo is destined for nero's very own palace, 408 00:31:56,115 --> 00:32:00,300 The lavish domus aurea, the golden house. 409 00:32:08,410 --> 00:32:12,980 This means the ingots belonged to nero himself. 410 00:32:14,683 --> 00:32:18,468 And the bou ferrer is sailing for portus. 411 00:32:19,738 --> 00:32:24,708 So she likely sinks before nero's death in 68ad. 412 00:32:30,816 --> 00:32:33,166 But there's one final question. 413 00:32:34,336 --> 00:32:38,105 Why did the bou ferrer and her imperial cargo 414 00:32:38,207 --> 00:32:41,241 Fail to make it to portus? 415 00:32:44,046 --> 00:32:47,447 The drained wreck offers some clues. 416 00:32:48,484 --> 00:32:50,968 The amphorae are off center, 417 00:32:51,070 --> 00:32:54,504 They've shifted towards the port side. 418 00:32:55,074 --> 00:32:59,076 Such a heavy cargo would never be loaded like this. 419 00:33:00,846 --> 00:33:05,882 So what could cause some 5,000 amphorae to move? 420 00:33:13,008 --> 00:33:17,644 Carlos believes that the bou ferrer runs into a storm. 421 00:33:19,848 --> 00:33:25,369 A large wave strikes the hull, causing the cargo to shift, 422 00:33:26,338 --> 00:33:30,273 The vessel to list to her port side, 423 00:33:30,376 --> 00:33:33,610 Making her impossible to steer. 424 00:33:34,780 --> 00:33:38,882 And allowing more waves to come over her decks 425 00:33:38,984 --> 00:33:42,202 And slowly fill her hold. 426 00:33:43,672 --> 00:33:45,572 Carlos: And there you are done, it's a matter of time, 427 00:33:45,674 --> 00:33:47,908 Maybe 20 minutes, maybe one hour, but you are done. 428 00:34:02,808 --> 00:34:04,775 Narrator: As rome masters the seas, 429 00:34:04,877 --> 00:34:08,045 Ships like bou ferrer are the empire's lifeblood, 430 00:34:08,147 --> 00:34:12,733 Carrying precious metals, slaves and especially grain, 431 00:34:12,835 --> 00:34:17,304 To and from portus and harbors all across the mediterranean. 432 00:34:18,474 --> 00:34:21,808 Spreading the power and influence of rome. 433 00:34:23,078 --> 00:34:26,747 Including a strategic base in modern day israel, 434 00:34:27,516 --> 00:34:30,067 What the romans called judea. 435 00:34:30,169 --> 00:34:33,003 Its capital, caesarea maritima, 436 00:34:33,105 --> 00:34:36,306 Stands at the crossroads of africa and asia. 437 00:34:38,110 --> 00:34:41,645 To the romans, it's the gateway to the riches of the 438 00:34:41,747 --> 00:34:46,166 East, an important source of grain and exotic spices. 439 00:34:48,370 --> 00:34:51,905 Transporting these treasures to rome requires a harbor. 440 00:34:54,476 --> 00:34:56,810 But there are major problems. 441 00:34:56,912 --> 00:35:00,781 No natural inlets protect from waves. 442 00:35:02,868 --> 00:35:07,404 A sandy coastline offers no solid footing for building and 443 00:35:07,506 --> 00:35:10,974 There's a constant threat of earthquakes. 444 00:35:13,278 --> 00:35:15,579 But according to historical records, 445 00:35:15,681 --> 00:35:18,615 Two decades before the birth of jesus, 446 00:35:18,717 --> 00:35:22,169 Roman engineers defy nature here. 447 00:35:23,672 --> 00:35:26,439 They construct a grand offshore harbor, 448 00:35:26,542 --> 00:35:30,844 Transforming caesarea into a wealthy trade hub. 449 00:35:31,947 --> 00:35:35,599 It's a remarkable feat of engineering, yet today, 450 00:35:35,701 --> 00:35:38,802 It's nowhere to be seen. 451 00:35:42,741 --> 00:35:44,641 For decades, investigators 452 00:35:44,743 --> 00:35:47,744 Like national geographic explorer beverly goodman, 453 00:35:47,846 --> 00:35:51,148 Have been trying to find evidence. 454 00:35:52,801 --> 00:35:54,434 Beverly: We have a pretty good idea of what the harbor might 455 00:35:54,536 --> 00:35:57,037 Have looked like, because the historian, flavius josephus, 456 00:35:57,139 --> 00:35:59,906 Left us a record. 457 00:36:01,910 --> 00:36:05,145 The entrance of the harbor had towers and statues. 458 00:36:06,181 --> 00:36:09,399 You can kind of picture it being this monumental harbor, 459 00:36:09,518 --> 00:36:12,602 Comparable to something you would see in rome. 460 00:36:14,206 --> 00:36:16,273 Narrator: But over the centuries, 461 00:36:16,375 --> 00:36:19,176 The harbor disappears. 462 00:36:20,879 --> 00:36:24,548 Only traces of this great roman outpost remain, 463 00:36:24,650 --> 00:36:27,167 Scattered on dry land. 464 00:36:29,605 --> 00:36:32,405 As for what's left of the harbor itself, 465 00:36:32,507 --> 00:36:36,443 The focus of beverly's investigation must be offshore. 466 00:36:40,315 --> 00:36:44,901 What she finds underwater is promising, but far from clear. 467 00:36:45,971 --> 00:36:48,438 Beverly: There's a lot of uncertainty about which parts 468 00:36:48,540 --> 00:36:51,041 Of the harbor are natural and which of them are the 469 00:36:51,143 --> 00:36:53,343 Artificial features. 470 00:36:54,563 --> 00:36:59,049 Narrator: There are shapes that could be natural or manmade. 471 00:37:00,602 --> 00:37:05,739 Meticulous investigation reveals they're resting on sand. 472 00:37:07,509 --> 00:37:10,543 There's no natural bedrock underneath. 473 00:37:11,780 --> 00:37:17,033 It's a sure sign they're all manmade and could be 474 00:37:17,135 --> 00:37:20,170 Part of the lost harbor. 475 00:37:21,039 --> 00:37:22,706 Beverly: Everything that you look at, 476 00:37:22,808 --> 00:37:25,642 You realize it was put there, it was placed there and then 477 00:37:25,744 --> 00:37:28,078 You start to think about that, you start to really understand 478 00:37:28,180 --> 00:37:31,815 The scale of what this place was like. 479 00:37:33,201 --> 00:37:36,002 Narrator: To work out the size and orientation of the ancient 480 00:37:36,104 --> 00:37:39,539 Harbor, the team must first create a comprehensive 481 00:37:39,658 --> 00:37:43,009 Sonar map of the seafloor. 482 00:37:45,514 --> 00:37:48,415 Beverly: So this kind of survey is getting our baseline 483 00:37:48,517 --> 00:37:50,767 Maps, our basic information, that from that, 484 00:37:50,869 --> 00:37:53,870 We can go and find targets. 485 00:37:55,073 --> 00:37:57,707 Narrator: Combining years of diving surveys with these 486 00:37:57,809 --> 00:38:02,312 Latest scans, it's possible to drain the waters from the 487 00:38:02,414 --> 00:38:06,733 Eastern mediterranean and expose what's left of the 488 00:38:06,835 --> 00:38:10,870 Ancient harbor of caesarea maritima, 489 00:38:12,040 --> 00:38:16,493 For the first time in almost 2,000 years. 490 00:38:17,913 --> 00:38:21,715 As the water recedes, it lays bare a strangely shaped 491 00:38:21,817 --> 00:38:24,934 Structure on the seafloor. 492 00:38:25,904 --> 00:38:30,273 This long jagged mass of rock resembling a natural reef 493 00:38:30,375 --> 00:38:34,344 Stretches into the empty basin. 494 00:38:36,081 --> 00:38:39,466 Opposite, another wider mass reaches out, 495 00:38:39,568 --> 00:38:41,835 Almost a third of a mile. 496 00:38:46,641 --> 00:38:51,044 These are the remains of the breakwaters of a massive port, 497 00:38:51,146 --> 00:38:54,381 That spanned over 40 acres, 498 00:38:54,483 --> 00:38:57,967 The harbor of caesarea maritima. 499 00:39:00,038 --> 00:39:03,640 So how did the romans build something so monumental on 500 00:39:03,742 --> 00:39:06,443 Nothing more than sand? 501 00:39:15,504 --> 00:39:18,138 Narrator: Over 2,000 years ago in judea, 502 00:39:18,240 --> 00:39:22,876 Romans perform an engineering miracle at a place called 503 00:39:22,978 --> 00:39:25,678 Caesarea maritima. 504 00:39:28,617 --> 00:39:31,401 They construct the largest artificial harbor in the 505 00:39:31,503 --> 00:39:34,037 Ancient world. 506 00:39:36,308 --> 00:39:39,776 Revealed for the first time in centuries, 507 00:39:39,878 --> 00:39:43,480 The foundations of the huge harbor walls had to be built 508 00:39:43,582 --> 00:39:45,965 On shifting sand. 509 00:39:46,068 --> 00:39:49,069 It seems an impossible task. 510 00:39:51,006 --> 00:39:54,474 Beverly goodman has come to the site of the ancient harbor, 511 00:39:54,576 --> 00:39:58,111 To take samples from its underwater remains. 512 00:40:06,371 --> 00:40:10,707 The team insert a pipe deep into the seafloor. 513 00:40:10,809 --> 00:40:14,344 To draw up traces from the past. 514 00:40:19,050 --> 00:40:23,903 (mechanical clicking). 515 00:40:26,541 --> 00:40:29,959 Beverly: So, we managed to get a core in very deep. 516 00:40:30,378 --> 00:40:33,113 Next up, is to open it, see what we have inside, 517 00:40:33,215 --> 00:40:35,799 See what surprises wait for us. 518 00:40:40,372 --> 00:40:42,255 Oh, good. 519 00:40:42,340 --> 00:40:45,508 Alright, we got quite a few changes we need to log here 520 00:40:45,610 --> 00:40:47,577 And take a look at. 521 00:40:48,780 --> 00:40:50,413 Wow, this is kind of surprising, 522 00:40:50,482 --> 00:40:53,800 I didn't think it was gonna have quite so much variation. 523 00:40:54,803 --> 00:40:57,537 On the upper part of the core, we have this natural sediment. 524 00:40:57,639 --> 00:41:00,707 We really have this period where the site is nearly 525 00:41:00,809 --> 00:41:03,243 Abandoned for many, many years. 526 00:41:03,345 --> 00:41:06,012 Then as we go down the core and we start to get periods 527 00:41:06,114 --> 00:41:07,780 Where there's actually people around, 528 00:41:07,883 --> 00:41:11,835 We start to see more pottery, we start to see rubble, 529 00:41:11,937 --> 00:41:14,471 We start to see changes that relate to the fact that people 530 00:41:14,573 --> 00:41:16,873 Were there and they were influencing the environment, 531 00:41:16,975 --> 00:41:19,108 They were building. 532 00:41:19,211 --> 00:41:21,411 Narrator: The sediment layer from the time of the harbor 533 00:41:21,513 --> 00:41:24,013 Reveals a clue. 534 00:41:27,135 --> 00:41:30,537 The rubble contains an unusual mineral. 535 00:41:31,640 --> 00:41:36,709 A particular type of volcanic ash, called pozzolana. 536 00:41:38,213 --> 00:41:41,147 It's not natural to this region. 537 00:41:41,249 --> 00:41:45,502 The source is over 1,000 miles to the west, 538 00:41:45,604 --> 00:41:49,005 The slopes of mount vesuvius in Italy. 539 00:41:54,079 --> 00:41:58,381 Why bring pozzolana all this way? 540 00:42:00,969 --> 00:42:06,339 The reason still lies on the seafloor of caesarea maritima. 541 00:42:08,410 --> 00:42:12,362 Traces of a revolutionary roman invention. 542 00:42:13,415 --> 00:42:16,416 A new kind of concrete. 543 00:42:19,170 --> 00:42:21,471 Beverly: We could actually see those elements of the concrete 544 00:42:21,573 --> 00:42:23,673 And know that this is the fingerprint of the 545 00:42:23,775 --> 00:42:25,775 Presence of the romans. 546 00:42:27,879 --> 00:42:30,747 Narrator: Historical records reveal that roman engineers 547 00:42:30,849 --> 00:42:34,567 Ferry tons of pozzolana to caesarea. 548 00:42:35,103 --> 00:42:37,170 Beverly: To imagine that they are shipping across the 549 00:42:37,272 --> 00:42:41,574 Mediterranean 2,000 years ago, essentially barges that have 550 00:42:41,676 --> 00:42:43,610 Volcanic ash coming from Italy, 551 00:42:43,712 --> 00:42:45,211 All the way across the mediterranean to the eastern 552 00:42:45,313 --> 00:42:48,114 Mediterranean is really something phenomenal. 553 00:42:49,367 --> 00:42:52,502 Narrator: The romans use concrete to build on land, 554 00:42:52,604 --> 00:42:56,739 Throughout their empire, but then they realize that by 555 00:42:56,841 --> 00:43:00,310 Adding the pozzolana ash to their concrete mix, 556 00:43:00,478 --> 00:43:03,246 They can use it underwater too. 557 00:43:03,348 --> 00:43:05,348 Jon: So they're bringing this volcanic ash in, 558 00:43:05,450 --> 00:43:08,001 Then mixing it with the stone rubble and the lime to create 559 00:43:08,103 --> 00:43:11,471 Concrete, but it only hardens when you pour water on it. 560 00:43:11,573 --> 00:43:13,706 So if you take it into the sea, once it hits the water, 561 00:43:13,808 --> 00:43:15,842 It hardens. 562 00:43:17,245 --> 00:43:20,313 Narrator: It's known as hydraulic concrete. 563 00:43:20,415 --> 00:43:24,601 And it's a huge milestone in the history of construction. 564 00:43:29,107 --> 00:43:33,476 For years, how the romans used this modern building material 565 00:43:33,578 --> 00:43:37,547 To create this harbor remains a mystery. 566 00:43:39,401 --> 00:43:43,670 But finds on the seabed provide a clue. 567 00:43:45,307 --> 00:43:47,607 Beverly: So one of the findings in caesarea is 568 00:43:47,709 --> 00:43:50,443 Preserved wood, wood from 2,000 years ago 569 00:43:50,545 --> 00:43:54,647 That was used to create the framework for them to pour the concrete, 570 00:43:54,766 --> 00:43:58,201 To create these large structures of the harbor. 571 00:43:59,838 --> 00:44:03,740 Narrator: 2,000 years ago, the romans work with concrete, 572 00:44:03,842 --> 00:44:06,843 Just like we do today. 573 00:44:08,313 --> 00:44:12,181 They build wooden structures, known as caissons, that hold 574 00:44:12,283 --> 00:44:17,170 Liquid concrete in place and then drop them into the sea. 575 00:44:18,940 --> 00:44:22,208 Flooded with seawater, the mixture solidifies, 576 00:44:22,310 --> 00:44:26,112 Creating solid concrete blocks. 577 00:44:26,981 --> 00:44:31,300 Manmade bedrock, on which to build the first artificial 578 00:44:31,403 --> 00:44:34,704 Harbor in the world. 579 00:44:38,877 --> 00:44:43,279 We now know how caesarea maritima was constructed. 580 00:44:44,482 --> 00:44:47,600 But there's one mystery left. 581 00:44:47,702 --> 00:44:52,405 Contemporary accounts suggest the harbor disappears, 582 00:44:52,507 --> 00:44:56,309 Barely a century after its construction. 583 00:44:59,180 --> 00:45:01,514 Amongst the drained ruins, 584 00:45:01,616 --> 00:45:04,367 There's a clue to what happened. 585 00:45:05,970 --> 00:45:10,173 All the elements of the harbor still remain, 586 00:45:10,275 --> 00:45:14,077 But they lie shattered on the seafloor. 587 00:45:22,203 --> 00:45:26,372 So what might have led to the collapse of the harbor? 588 00:45:30,111 --> 00:45:32,044 In the core samples, 589 00:45:32,147 --> 00:45:35,748 Layers of sediment from after the construction of the harbor, 590 00:45:35,850 --> 00:45:38,768 Help build a picture of events. 591 00:45:38,870 --> 00:45:41,137 Beverly: When we find these layers and when we see it's 592 00:45:41,256 --> 00:45:44,674 Not like the deposits that are above or below it, 593 00:45:44,776 --> 00:45:48,845 So we can see that it's in fact an isolated incident. 594 00:45:50,248 --> 00:45:53,516 Narrator: These layers suggest that something cataclysmic 595 00:45:53,601 --> 00:45:55,768 Churned up the sediment. 596 00:45:56,905 --> 00:45:59,539 Beverly: There is a reference that talks about a possible 597 00:45:59,641 --> 00:46:03,209 Tsunami in the year 115 ad. 598 00:46:10,635 --> 00:46:12,668 Maybe that's the event, maybe not, 599 00:46:12,771 --> 00:46:15,538 It does coincide nicely with the finds that we have and 600 00:46:15,640 --> 00:46:17,740 The ages that we see. 601 00:46:17,842 --> 00:46:21,010 Narrator: It seems likely that this great artificial harbor 602 00:46:21,112 --> 00:46:23,746 Is reduced to a fraction of its former glory, 603 00:46:23,848 --> 00:46:27,800 Just as rome tightens its grip on the mediterranean world. 604 00:46:27,902 --> 00:46:32,472 But caesarea's part in the history of the roman empire is not over. 605 00:46:34,943 --> 00:46:37,643 The romans apply the power of their wondrous concrete 606 00:46:37,745 --> 00:46:41,948 Everywhere, establishing ports and harbors across the 607 00:46:42,050 --> 00:46:45,168 Mediterranean wherever they need. 608 00:46:45,270 --> 00:46:47,603 Jon: This is the first and last time the mediterranean 609 00:46:47,705 --> 00:46:50,540 Was under the control of one power. 610 00:46:50,642 --> 00:46:52,975 It wasn't a space where wars were fought, 611 00:46:53,077 --> 00:46:55,745 It was a place where trade took place and that's why the 612 00:46:55,847 --> 00:46:58,548 Romans have this kind of relationship with the sea, 613 00:46:58,650 --> 00:47:01,434 It's our sea, mare nostrum. 614 00:47:03,972 --> 00:47:07,006 Narrator: 1,000 years will pass before other nations, 615 00:47:07,108 --> 00:47:10,176 Portugal and Spain, come close to matching 616 00:47:10,278 --> 00:47:12,712 What the romans achieve. 617 00:47:12,814 --> 00:47:17,099 Domination of the known world, through an empire of the seas. 618 00:47:18,803 --> 00:47:20,002 Captioned by cotter captioning services.