[narrator] They're watching you.
More than 6,000 satellites circle the Earth.
Every day, they uncover new mysterious phenomena
that defy explanation.
From the skies,
the $37 billion treasure trove.
There are so many structures with so many secrets told.
[narrator] The 500,000 square mile cipher.
These markings can explain one of the deadliest periods in human history.
[narrator] And the lost cit of the ancient super warrior
There are all kinds of artifacts
pointing to the fact that this belonged to Alexander the Great.
[narrator] Baffling phenomen Mysteries from space.
What on Earth are they?
[theme music playing]
February 13th, 2022.
Northeast Poland.
Alex Ritchie is trekking through this frozen landscap
drawn by codes captured from the skies.
[Ritchie] It's very difficult to imagine
what they would be out here in the middle of a--
of a dense and very remote forest.
[narrator] A laser scan of a nearby patch of woodlan
has exposed these markings hidden beneath the tree line
[Walters] What the lidar has uncovered,
is a series of these huge zigzagging patterns
that appear to be carved right into the landscape.
[Janulis] It's an odd-lookin collage of lines.
It almost looks like an abstract painting.
[narrator] Further analysis reveals
the strange shapes cover an area
of one square mile.
[Janulis] The more you look the more you see.
So what seems to be going on here
is more than just some zigzags.
[narrator] Ritchie moves deep into the forest,
heading for the image coordinates.
Well, the lidar has brought me to this place.
And, well, there is a lot of undergrowth.
This is a-- clearly the foundation of some sort of building.
[narrator] A few hundred feet away, sits another structure.
One that appears to serve a defensive purpose.
Oh, my goodness.
Look at this.
Gigantic...concrete structure.
The walls must be ten feet thick, if not more.
What's so amazing is, as I look around, you can see
that there are more than one of these strange structures
in this forest.
And they're just massive.
[narrator] In total, Ritchie finds
over 200 similar structures littering the forest.
Etched into one of them is a warning.
Here's our clue.
[reading German]
[In English] Which means,
unauthorized personnel are not allowed to go in.
[narrator] The aerial image has uncovered the remains
of what appears to be a vast Nazi compound,
swallowed by time.
It's just extraordinary what remains on this site.
What was this huge complex hidden in the forest?
[narrator] Experts turn to declassify Nazi files.
They reveal something extraordinary.
The critical turning point in German history
occurs at this complex.
[Janulis] These bunkers were the headquarters
of the German Army High Command.
This is where they coordinated and planned
the invasion of Russia.
[narrator] In 1939,
Hitler forms an uneasy pact with Joseph Stalin
to ensure that he will not interfere
with his planned assault on Poland.
But the following year he betrays his ally
and issues an order to invade Russia.
Codenamed Operation Barbarossa.
[Auerbach] This was not meant simply to weaken the Soviet Union.
But to remove the threat
posed by, for all time.
[narrator] In the run up to the invasion,
Hitler constructs the comple in the image
for 40 of his top generals
and 1,500 officers and soldiers.
[Ritchie] So, this was a huge complex.
Like a spider web of power
for the running of the eastern front.
[narrator] In June, 1941.
Three million Nazi troops
and hundreds and thousands of vehicles and planes
sweep into Russia.
The largest, most powerful invasion force in history.
[Cavell] They were hoping the Soviet military would fail.
And fall within ten weeks or less.
But they didn't.
[Auerbach] They miscalculated in one very, very important way,
which is that Russia's never gonna run out of three things.
Land, cold and guys.
[narrator] Fierce Soviet resistance
stalls the German advance towards Moscow.
And by November, 1941,
730,000 German soldiers
lie dead in the sleet and sn of the eastern front.
[Janulis] Operation Barbaros
was one of the most horrific campaigns inhuman history.
Both, for the attackers and the defenders.
[gunfire]
[narrator] The Nazi's failur
to swiftly overrun the Red army infuriates Hitler
Who takes personal control of the operations at the site in the image.
But the slaughter continues
Culminating with the Nazis' surrender at Stalingrad.
A siege which leaves a further half a million German soldiers dead.
With the loss at Stalingrad,
Germany loses all of its forward momentum.
From that moment until the bitter end,
Germany is retreating and defending.
[Janulis] It was a war o attrition.
It chewed up the German army and spat it out.
Basically, Hitler blew everything he had
trying to take a country that wouldn't give up.
[narrator] The site in the image
is where Hitler makes his greatest tactical error
One that ultimately costs him the war.
Yet, as Ritchie continues to explore,
she discovers it's dark secrets don't end there.
Oh, my goodness.
Now, that's amazing.
It's some sort of shaft but I can see
that it leads to a huge chamber, by the looks of it.
[narrator] The Nazi base, it appears,
sits on top of a man-made subterranean world.
It's as if there's a whole underground city here.
What was it doing in this forest
in the middle of nowhere?
[narrator] Coming up...
The hunt for Hitler's gold.
[Janulis] We've only scratched the surface
of what the Germans were up to out here.
[narrator] And terror rises from the wastelands.
If you don't get treatment,
you die.
[narrator] Lured by strange markings in a remote Polish forest,
Alex Ritchie has discovered a vast secret base
used by Hitler for his failed invasion of Russia.
It is littered with hidden chambers and tunnels.
This is not just a city that was built overground.
It was also built underground.
It's not unusual for Nazi bunkers to have underground areas,
but the scale of these underground chambers
is massive.
Why did they need them?
[narrator] Ritchie speculate the chambers could have play
a part in the looting that took place
during Hitler's battles with Stalin.
[Ritchie] The Nazis were greatest looters or arts and artifacts
that the world has ever seen
And it has always been a mystery as to what treasures were kept.
[narrator] During the Nazis retreat from Russia,
they returned with over one million pieces of art and other treasures.
Pillaged from estates and museums.
Even today, $37 billion worth of their wartime heis
remains unrecovered.
One of the major treasures that we know the Germans stole
was something called the Amber Room,
from the royal palace in St. Petersburg.
This thing was ridiculous.
It was known as the eighth wonder of the world.
[Auerbach] The Amber Room is one of innumerable treasures
looted by the Germans.
The ultimate fate of which is unknown.
[narrator] A gift from a Prussian king to Tzar Peter the Great,
the room's panels are inlai
with over six tons of amber, gold, silver and precious gems.
[Morgan] It is reported, when you entered the room,
it had this breathtaking quality.
It had a means of dazzling people.
Um, and that's why it was something that was fit for a king.
[narrator] The Nazis dismant the Amber Room in 1941,
and ship it toward the site in the image
before it disappears from history.
There's a personal account, indicating that a number of trucks
carrying an unidentified cargo
made their way to this bunker complex.
And that they were quickly unloaded.
And the belief is that
maybe the Amber Room can still be found there, to this day.
[Ritchie] This is a really remote and dense forest.
It would be an ideal place to hide something.
[narrator] The role this complex and its hidden chambers
played in the looting of Russia
remains to be discovered.
As Ritchie continues to explore the area,
she finds another mysterious relic of the Nazis' time here.
Oh, my goodness.
Wow.
Now that is something I did not expect.
It's a huge, huge concrete structure.
And yet, what's very strange is that the bottom
is a kind of canal with water in it.
[narrator] Nazi record revea the giant structure
is a lock, sitting on what's known as the Masurian Canal.
[Auerbach] The Masurian Cana was started in 1911.
When this are was still part of the German Empire.
The goal was to bring trade and prosperity to this remote outpost.
[narrator] The advent of World War I
brings construction of the canal to a halt in 1914.
But two decades later,
work resumes under the command of Hitler
His aim is to connect the giant lock in the woods
to a nearby river and onwards to the Baltic Se
This canal represents, basically, a naval gateway
to anywhere you wanna be in the world.
Why were the Germans building such a large canal system here?
[narrator] The canal's proximity to the Nazi command center
fuels speculation that it ma have served a clandestine
and highly controversial purpose.
We know many of the Nazis,
particularly high-ranking ones,
were planning escape routes
at the end of the war.
They could read the writing on the wall.
[narrator] During the closing stages of World War II,
Nazi officials find themselves trapped
between advancing Allied and Russian forces.
Fearing bloody retribution for their war crimes,
many looked to sympathetic nations for protection.
To be captured by the Red army
was almost a guarantee that you would be killed.
So there was definitely a sense of rats fleeing a sinking ship.
[narrator] The canal, when completed,
would provide a naval route
from the Nazi complex to the Atlantic Ocean, and beyond.
This plan, if true, would have seen Nazi officials escape from this region
out to the Baltic, and all the way to South America.
[Janulis] Perhaps, this canal system was plan B
for this base.
Make your last stand there.
But if everything goes wrong,
you have an escape route.
[narrator] Today, much of this giant complex
and its subterranean chamber
remain unexplored.
Their contents, a mystery.
Eight decades after the war ended
it is an enigma revealed from the skies,
waiting to be decoded.
[Ritchie] There are so many structures in the forest
with so many secrets still to tell.
[Janulis] This discovery is showing us,
That we've only scratched the surface
of what the Germans were up to out here.
[narrator] Coming up...
The mystery ancient mega plague.
Many historians say that this would have been
the worst time in human history to be alive.
[narrator] And a secret rises from the sands.
[Horton] This is a highly significant locatio
Because this was the cradle of civilization.
[narrator] October 9th, 2018
A satellite flying over Asia,
scans the seemingly featureless plains
of Southern Kazakhstan.
And captures this image.
[Munoz] The thing that draws me eye
are these random pitting or scarring marks
on the landscape.
And there doesn't really seem to be any rhyme or reason to them.
The little, kind of, radiating star shapes,
hundreds, thousands, tens of thousands of them,
they're just bizarre.
[narrator] Scientists estimate the mystery patter
covers half a million square miles.
And area three times the size of California.
And the mystery of this giant desert code
doesn't end there.
Here's where it gets really weird.
Locals who have gone near this area,
report these apple or egg-sized lumps
in their groins or in their neck.
[Kays] Apparently, these are pretty serious,
and if you don't get treated, you can die in a couple of days.
[narrator] Tests reveal the victim succumbed
to one of the most feared diseases on Earth.
One, that by some estimates
has killed five times as many people
as the ravages of World War II.
[Ruben] Strangely enough, these markings
can help to explain one of the deadliest periods in human history.
The Bubonic Plague.
Also known as the Black Death.
[rats squeaking]
[narrator] In 1347 CE,
the inhabitants of Eastern Europe
begin suffering from mysterious ailments
and pustulating skin conditions.
[woman coughing]
Within five years,
25 million people are dead.
Almost one-third of Europe's population.
[Rice] The bubonic plague burned through Europe,
causing suffering and death
on a truly unimaginable scale.
[Anthony] No one knew where it came from,
or how it spread.
You couldn't treat it.
Many historians say that this would have been
the worst time in human history to be alive.
[narrator] Devastated survivors
irrationally blamed the disease on gypsies,
witches, or Jewish people.
Thousands are tortured and burned to death.
It's not until the turn of the 20th century
that scientists identified the real culprit.
A bacteria carried by infected fleas.
Rats carry fleas.
And the theory was that when plague infects fleas,
the fleas can bite humans, transmitting the disease.
And more rats leads to outbreak like the Black Death.
But there's a problem with this theory.
The latest research suggest that
14th century outbreaks of plague
did not correspond to increases in rat population.
So something else must have triggered these outbreaks.
[narrator] Some scientists now think another animal
is to blame for the mass death.
One that makes it home in the vast steps of Kazakhstan.
This unusual pattern that we see
is actually caused by gerbils.
As they create their burrow
they kill all the plant life above it.
And that leaves these big patches of barren earth
that reflect really well in satellite images.
[narrator] Known as great gerbils.
These rodents grow to around one foot in lengt
and live in family groups.
Numbering in their millions
a three acre patch of deser
can contain over 1,000 burrows,
creating vast patterns visible from space.
Gerbils, as cute as they are,
can also be the unwitting host of Yersinia pestis,
the bacteria that caused the Black Death.
[narrator] Scholars believe that Yersinia pestis
originated in this part of the world
some 6,000 years ago.
It persists in the guts of gerbil fleas for centurie
In the middle ages, this festering, biological time bomb explodes
when the plague-carrying insects hitch a ride westwards.
[camel grunting]
[Anthony] It seems as though fleas from these gerbils
were able to attach themselves to Mongols and their camels
traveling along the Silk Road into Europe.
And that might have been the true source of the plagu
[narrator] What's more...
Fluctuations in the gerbil populations
help explain why so many waves of the Black Death
swept west during the 14th century.
[Kays] Scientists looked at weather patterns
that drive gerbil boom birth cycles.
And what's amazing is those synced up with
really bad outbreaks of bubonic plague in Europe
[narrator] In the late middle ages,
advances in hygiene and medicine
suppressed the plague in Europe.
In the 1940s,
Soviet authorities try a very different approach
to eliminating the disease in Kazakhstan.
They declare war on the gerbil.
[Rice] They were spraying the burrows with DDT.
They were burning the lands so the gerbil would have nothing to eat.
The Soviet Union was so hell bent on eradicating the plague,
that it actually conscripte thousands of civilians
to take spoonfuls of grain tainted with poison
and pour them into these little burrow holes,
in an attempt to kill off the entire gerbil population.
It wasn't a bad idea but it didn't work.
The gerbils soon came back and brought the plague right back with them.
Because of gerbil populations like the one in this image,
the plague is endemic to 40 percent of the area of Kazakhstan.
[narrator] Today, with the plague still so widespread in Kazakhstan
images such as this play a key role
in predicting when the next outbreak may erupt from these lands.
Because the gerbil burrows have this recognizable, pale, star shape,
our approach for controlling them could be much more targeted
[narrator] Death it transpir has many different faces.
[Kays] It's really amazing that this disease,
which has been so important in human history...
That now we can manage it by watching gerbils from space.
[narrator] Coming up...
A secret site that helped change the world.
It becomes the largest single industry
the world has ever seen.
[narrator] And the city built on bones.
[Chamberlain] This is just incredible to think
that this entire city
might have been lost to history forever.
[narrator] June 12th, 2019.
An aerial survey of the Arizona desert
captures this image.
[Walters] This is a rugged, mountainous desert.
And then there's this perfect, elongated, oval
etched into the terrain.
[Kourounis] And within that oval there are other weird shapes
Including what almost looks like a figure eight
and a few small buildings.
It's the shapes that really get me.
[narrator] Analysis reveals the shapes appeared
to be fashioned from asphalt or concrete.
In total, some 20 miles of these roads to nowhere
crisscross the isolated facility.
This is inaccessible, very rugged terrain.
And yet, clearly, a lot of effort has gone into building this.
Why would you do that?
[narrator] The compounds location could offer a clue
One really interesting fact about this particular image
is that it's not very far from the Yuma Proving Ground.
[narrator] The Yuma Proving Ground
is one of the largest military test sites on Earth
A 1,300 square mile laborato
for testing all most every piece of equipment
in the US arsenal.
A proving ground is just that.
It's a place where you test new things.
The Yuma Proving Ground
has the longest overland artillery range
in the entire United States.
And the most well-equipped helicopter weapons test range imaginable.
[narrator] During tests at Yuma,
troops unleash around half a million munitions a year.
[gun firing]
And drive prototype vehicle over 200,000 miles.
These roadways within this perimeter
could be used to test things like tanks
and other kinds of all-terrain vehicles.
[narrator] However, others think this site doesn serve a military purpose.
If you wanted to really test how rugged your vehicle is,
why would you pave so many of the roads
in your proving grounds?
Proving grounds aren't just operated by the military.
You also have civilian industries
that need these secure and private locations
to put new products to the test.
I think that this Arizona facility
is the Chrysler Proving Grounds.
[narrator] The secretive facility
has its origins in the aftermath of World War II.
As peace returns to the US,
millions of households go on a spending spree.
In the wake of World War II
there is an explosion in car ownership.
[Kourounis] Americans fell in love.
It was all about how the automobile
represented prosperity and freedom.
[narrator] Between 1946 and 1955,
US car production quadruples
The 1944 Highway Act
also authorizes the construction
of 40,000 miles of roads.
Replacing rough tracks with paved arteries connected the nation.
You had all this infrastructure popping up
that could support that.
We see the advent of drive-thru restaurants,
drive-in movie theaters.
[Kerley] There is this entir post world culture
that's really built around the car and mobility
And it becomes really a part of the American life.
[Auerbach] The automotive industry doesn't just become
the largest industry in America.
It becomes the largest, single industry
the world has ever seen.
[narrator] The post war economic boom
also fuels an explosion
in the number of people taking vacations.
[narrator] In the 1950s
more than 80 percent of such travel is taken by car.
With each trip averaging 600 miles.
Trips which test these new generation of vehicles
to the point of destruction
It's one thing to build a car
or anything, for that matter, on paper.
It's another thing entirely to take it out in the real world
driven by real people.
[narrator] During the '50s,
America's car makers construct several sites
like the Chrysler Proving Ground
to road test their latest models.
The large banked oval tracks,
they're typically used for speed testing.
Then in the middle there's a grid.
Now that simulates a city traffic system.
And then there's also access to steep grade mountain roads.
Cars were driven endlessly
around these tracks to evaluate every component
to make sure that it was able to withstand the stress.
[narrator] Before selling the site in 2006,
Chrysler uses the proving ground
to put countless classic cars through their paces.
Cars that go on to define the lives and adventures
of generation of Americans.
These testing facilities were indispensable
for producing the cars that you and I enjoy today.
[narrator] Coming up...
A mystery rises from the desert.
Whatever it is, it's been there for a long time.
[narrator] And a toxic time bomb.
The word apocalyptic comes to mind.
[narrator] In 1959,
the first of 120 Corona spy satellites
takes to the skies.
Over the next decade they capture images
of more than one and half million square mile
of the Earth's surface.
For today's historians,
these declassified images
are an archaeological treasure trove.
They capture imagery of sites that have long since been covered over.
And changed beyond recognition.
Some of these sites have been built on since the '60s.
And so these images give us a snapshot back in time
of what the area would have looked like.
[narrator] When analysts stu a 1966 Corona photograph
of Northern Iraq,
they discover something not visible
in modern satellite images.
My eye is drawn immediately to the enormous
rectilinear structure in the center of it.
[Ruben] It has thick walls.
It looks like it's defensive in nature.
Like a fort.
Whatever it is, it's been there for a long time.
[narrator] The location of the mystery structure intrigues analysts.
It sits inside this so calle Fertile Crescent.
A vast middle eastern regio which was home
to some of the earliest civilizations in human history.
[Horton] This is a highly significant location.
Because it was the Cradle of Civilization.
And the place where urbanism really develops.
[Janulis] This landscape is incredibly, historically rich.
Almost everybody has conquered or have come through here.
[narrator] When archaeologis deployed drones to study this site,
they discover an array of structures,
including a temple and other monumental buildings.
[Chamberlain] When the drones go in,
they find it's not just this one, big fortress.
There are other buildings.
This looks like a large, ancient city.
[Ruben] What we're looking at is clearly a complex settlement
belonging to someone with power.
[narrator] The lost city covers an area
equivalent to 100 football fields.
Excavations suggest it was constructed
around two and a half thousand years ago,
by order of the greatest warrior in history.
There are all kinds of artifacts that are pointing to the fact
that this belonged to Alexander the Great.
[narrator] Born in 356 BCE,
Alexander becomes the kind of Macedonia at the age of 2
Before embarking on a campai of conquest without parallel
Alexander was perhaps one of the most unique
conquerors in history.
His tutor was Aristotle, who made his mind razor shar
No one was better suited to conquer the world than Alexander the Great.
[yelling]
[narrator] Deploying revolutionary military tacti
such as the phalanx,
within five years, his forces had vanquished
Greece, egypt and Turkey.
Alexander is just crushing his competitors.
He is dominating the known world,
except for this one other land.
Persia, run by Darius the Third.
[narrator] In 331,
Alexander's 50,000 strong ar
advances through the region in the image
before attacking the Persian at the battle of Gaugamela.
[horses neighing]
Deploying fast strike cavalry charges,
his soldiers overcome Darius' forces
despite being outnumbered five to one.
Alexander the Great was a military genius.
He didn't rely on numbers to win wars.
He relied on tactics and strategy.
[Ruben] It's because of victories like this
that Alexander is known as Alexander the Great.
[narrator] Alexander goes on to conquer
a two million square mile empire
and remains undefeated in battle.
The lost city appears to have been built
to ensure his exploits aren't just recorded on the battlefields
but are also immortalized in stone.
One of the ways that Alexander made his mark on
and held the lands that he conquered
was by building vast cities there.
Maybe this city was founded
to celebrate the victory in Gaugamela.
[narrator] The fort discover in the satellite image
guards a military route into the Persian empire.
It's also a reminder to his new subjects
of Alexander's crushing defeat of their leader.
[Chamberlain] To consolidate the victory,
he builds a city to say,
"Guess what? You are now part of my empire.
Look at me. I'm great."
[narrator] Over the followin millennia,
Alexander's city is swallowe by the sands.
Only to be revealed once mor from the skies.
[Chamberlain] This is just incredible to think
that now that we have this image,
it's exposed this entire city
that might have been lost to history forever.
[narrator] Coming up...
The mystery mega wound.
We have seen this unusual spike in illnesses
amongst the people that live there.
[narrator] May 26th, 2020.
A satellite above the Caribbean island of Jamaica
photographs something bizarr
Here we are in an enormous rain forest.
Right in the middle we have this desolate, red patch.
[Kourounis] The word apocalyptic comes to mind
as if it's a giant scar across the landscape.
[narrator] The red stain spreads over one square mile
[McRobbie] If you look even closer,
you can see that the Earth is,
sort of, pockmarked with these regular circles.
[Okereke] There are dozens of these circles
and they're spread out in these clear rows.
It's really odd.
[narrator] Geologist Devin Dennie
discovers disturbing local reports
that could offer a clue.
One thing we have seen lately
is this unusual spike in illnesses
amongst the people that live there.
[narrator] Since the appearance of the red scar,
countless Jamaicans living nearby
have complained respiratory illnesses and skin condition
This spike of illness could be coming
from having more dust in the air.
More red dust.
And that is a sign of what we may be looking at here
is a bauxite mine.
[narrator] Bauxite is the main ore used
to produce 65 million tons of aluminum,
worldwide, each year.
It's also a primary source of gallium.
A rare earth metal of vital importance to tech industries.
For the longest time, we've used silicon in our microchips.
But recent studies have demonstrated
that gallium is more than a thousand times more conductive.
[Okereke] This makes it extremely valuable for use of electronics.
Which is a market that's obviously growing exponentially.
[narrator] Around 367 millio metric tons of bauxite
is mined globally each year
It's importance to the futur of the tech center
means that one country is rapidly expanding its interest
in bauxite mining.
The Chinese government is desperate to control the mineral market.
So Beijing has been pouring billions of dollars into poorer nations
with large, natural deposit of these materials.
[cheering]
The plan is monopolize control of rare earth minerals
and not only is that a good economic plan,
but it would give China a tremendous amount of global power.
[narrator] Over the past decade,
China has launched a trillion dollar global development fund.
Of that, Jamaican authoritie accept $300 million
in exchange for control of the mine in the image.
What we're seeing from China
is a kind of modern day colonialism.
Instead of invading other nations,
Xi Jinping is flexing his country's economic muscl
[narrator] Today,
China processes 80 percent of all rare earth elements.
That provides them with a gr over the global manufacturin
of anything from smartphone to fighter jets.
China wants to replace the US
as the next great superpower.
And mines, like the one in Jamaica,
are part of their plan to do it.
[narrator] To extract bauxit
miners strip vast areas of jungle
before blasting out the mineral rich rock
and crushing it in piles.
[Dennie] That could also be some of the features that we see on the image.
Some of these circles are actual piles of crushed bauxite.
[narrator] As well as releasing vast clouds of dust into the air,
the mine tailings seep into the water supply.
In mining when you extract the material you want,
you also get a lot of materials you don't want.
And those end up in separating pools as waste
that can sometimes be toxic
Many of the townspeople won't touch the water anymore.
Those who have say that it made the water undrinkable.
[narrator] Globally, air pollution causes
around five and half millio deaths each year.
The long term health effect of our tech obsession
on the people of Jamaica remains to be seen.
[Dennie] As long as populations continue to demand
high technology products,
their demand is going to be there.
For more mines like this one.
This red stain in the heart of the Jamaican countryside
isn't going anywhere.