Original subtitles

NARRATOR: They're watching you.

More than 5,000 satellites circle the Earth.

Every day, they uncover new

mysterious phenomena that defy explanation.

Murder and Masonic rituals in the wilds of Scotland.

HORTON: This is really weird.

I've never seen anything quite like it.

NARRATOR: The ghost soldiers of World War II.

They've become these almost mythological warriors that

the Germans just don't know how to deal with.

NARRATOR: And terror in the Arctic.

Somewhere down there is an unrecovered nuclear weapon.

NARRATOR: Baffling phenomena, mysteries from space.

What on Earth are they?

[theme music playing]

♪

March 10th, 2021.

The barren borders of south Scotland.

A wilderness of heathland, forest,

and something hidden from human eyes.

I'm really excited about this image, because it's

a genuine mystery that I'm really keen to unravel.

NARRATOR: The laser pulse of a LIDAR scanner has

revealed a bizarre structure concealed by dense forest.

There's something man-made here under the soil.

It looks like a giant jigsaw puzzle.

NARRATOR: Archaeologist Mark Horton is hiking into

these remote lands to investigate the new discovery.

HORTON: It's really weird -- it appears to be

a gigantic castle or fortress in these woods.

NARRATOR: Scotland's bloody history is reflected

in the number of castles here,

but they're always built on hills to dominate

the landscape.

There's no historical record of these structures at all,

and then there's a wood placed

on top of them, almost as if these ancient remains

are meant to be hidden.

NARRATOR: Much of the 1,800 square miles Scottish

borders are devoid of life or buildings.

But not far from the LIDAR structure,

Horton spots an outline that matches its scale and shape.

Wow, what an amazing castle.

It's all so complete.

NARRATOR: The hilltop stronghold may hold clues

to the mystery in the woods.

HORTON: It's got arrow slits, but also these holes

for artillery -- late medieval guns,

so we're talking 14th, 15th century, something like that.

And maybe the images I've seen in the LIDAR

might also be of that same sort of date.

NARRATOR: The walls are up to 40 feet high

and heavily fortified.

Incredibly small entrance.

You could hardly get a horse through there.

NARRATOR: To Horton, there's something

strange about this castle.

Inside, it's all so small.

You'd normally have an enormous castle courtyard, but actually,

this is the size of most people's living rooms.

It's kind of like a domestic house.

NARRATOR: This hilltop fortification

and structure in the woods

both sit on the frontier with Scotland's once bitter enemy.

We're right on the border between England and Scotland,

and of course, up until the 17th century,

there were different nations continually

at war with one another.

[indistinct battle noise]

NARRATOR: War between the English and Scots begins in

the 13th century and rages for 400 years.

The territory around the LIDAR image is contested fiercely,

becoming a medieval Wild West.

This border region was an area of complete lawlessness in

which bandits and raiding parties were killing everybody,

raiding people's stock, destroying their houses,

burning their farms,

and these were known as the border reivers.

NARRATOR: Reivers, meaning raiders,

hailed from both sides of the border.

They have no allegiance to the English

or Scottish crowns, just to their own family clans.

People here lived in very small

communities, and family ties were paramount.

The clan ruled all.

NARRATOR: With crops burned and food scarce in wartime,

cutthroat reiver clans take what they need by force.

Skilled horsemen and masters of arson and extortion,

they terrorized the Anglo- Scottish border for centuries.

SZULGIT: Sometimes, the reivers will be made out

to be these lovable rogues, but in actuality,

these were well-organized, deadly groups,

and it was more like a mafia.

NARRATOR: Modest farming folk are powerless to resist,

but the wealthy build fortified keeps

known as peel towers.

HORTON: They had to live in places like this,

because they were in fear of their lives.

There might also be castles further up

the valley associated with these border reivers.

NARRATOR: Bearing northeast, the archaeologist heads to

the greenery recently scanned by laser.

I think this must be the wood I've seen on the LIDAR image,

but actually, it's quite impenetrable.

NARRATOR: 15 acres of dense forest are

cordoned off with thousands of feet of wire,

much of it ill-maintained.

It's a bit of tumbled down fence,

I think, that might get me in here.

[groans]

♪

Something here -- kind of depression or ditch.

It's so faint,

very difficult to see.

NARRATOR: The ditches match the outline of the image.

I'm absolutely certain it's what I've seen

on that LIDAR image.

NARRATOR: But there are

no medieval fortifications whatsoever.

There's no masonry here.

There's no collapsed walls -- whatever it is,

this is really weird.

I've never seen anything quite like it.

NARRATOR: Coming up,

the cult of the invisible castle.

It's a place of secrecy and ritual.

NARRATOR: And Nevada's lost

multibillion-dollar treasure hoard.

It is a geyser of cash for anyone involved.

NARRATOR: Drawn by strange shapes revealed

by LIDAR aerial images,

archaeologist Mark Horton is in the wild Scottish borders.

I've never seen anything quite like it.

NARRATOR: He anticipated a ruined fort,

but these shapes are something else.

What's really odd is that we've got all

these tree stumps on the top of the bank.

This woodland is all a bit higgledy piggledy,

but actually, these stumps form a deliberate

straight line, as if they've actually been planned.

NARRATOR: Lines of rotting stumps match

the contours of the shapes in the LIDAR image.

Someone has planted hundreds

of trees to mimic a medieval fort.

HORTON: Those tree stumps, okay, they're old,

but they're clearly not medieval.

Maybe the whole structure is much more recent.

NARRATOR: The archaeologists scours

English military records.

After they defeat Scotland in 1745,

the English decide that to control this wild land,

they need to map it properly.

This old map from 1858

actually shows our fort.

It's defined by not a wall but a set of trees.

It's not a fort at all,

but part of a planned ornamental landscape.

NARRATOR: This isn't some medieval ruins.

It's a gargantuan garden, a bizarre castle plantation.

Stranger still, this mighty undertaking appears to

have been deliberately concealed in a forest.

Why would anyone go to the trouble

to create these weird features in the landscape?

NARRATOR: Searching the surrounding valley,

Horton finds that the weird plantation isn't

the only relic hidden in this corner of Scotland.

What's that over there?

It looks like a ruined building.

It's in awful condition.

NARRATOR: Father Time hasn't left much to go on.

These are graves.

That must be the east end.

So they also would originally have been around here.

Look, we've got more gravestones.

This must be a broken-down chapel.

NARRATOR: A chapel suggests this landscape wasn't always

so desolate.

HORTON: That makes me think that possibly this is

a big estate here, with a rich landowner

who had the money and resources to do

these fancy plantations,

but why would he put these weird

sort of castle-like features up on the landscape.

It still doesn't make sense to me.

NARRATOR: A ruined monument may hold a clue.

I can make out a sort of schematic skeleton

holding a lance.

He's holding an hourglass

to show the passage of time.

A skeleton with the scepter

and an hourglass is a classic symbol of death,

also known as the king of terrors.

NARRATOR: The king of terrors is rumored to

be a symbol of an infamously secretive society.

It's seen in Masonic texts, so it could suggest that we

are seeing a garden created by a member of the Masons.

NARRATOR: Freemasonry is the world's

oldest and largest fraternal organization.

SZULGIT: No one really knows the true origin of the Freemasons,

but several people say it began in Scotland

right around this area.

NARRATOR: Freemasonry in Scotland is born at

the turn of the 16th century,

cut from the rock that

builds Britain's great castles and cathedrals.

The Freemasons developed out of old stone masons, and it was

a way of ensuring that someone was suitably qualified

to do the job.

There was a secret language that

evolved in symbols, including a special handshake.

NARRATOR: As the building of cathedrals declines,

Masons accept honorary members.

The rich and influential are initiated in

strange ceremonies marked by obscure codes and rituals.

By the late 18th century,

the Masons are a powerful, clandestine cabal,

who count king George IV among their ranks.

One of the most famous of

the later Freemasons was the novelist Sir Walter Scott.

A lot of the pageantry of Freemasonry owes a debt

to Sir Walter Scott, because he was obsessed with medievalism.

NARRATOR: Scott is a Renaissance icon who

writes the legendary historical novel Ivanhoe .

His swashbuckling tales paint medieval Scotland

as a land of heroic chivalry,

while his epic ballads romanticized the outlaws

he calls the border reivers.

SZULGIT: He mythologized the reivers and the early period.

This idea of the past was adopted by

the Masons and became part of their tradition.

NARRATOR: Rich Masons honor Scott with extravagant

tributes to his obsession with medievalism,

coded messages to their most celebrated

member and to their Masonic brethren.

Landowners inspired by Walter Scott and his writings

create structures in the landscape to hark back

to a medieval past and the border reivers.

Freemasons obsessed with secret symbols

would have known what it meant.

NARRATOR: LIDAR has revealed a rotting cipher

grown from Scots pine and stout oak

and hidden by forest in the cradle

of Freemasonry.

But the strangest stories of this site

remain a mystery, safeguarded by Masonic oath.

It's tantalizing to think what might

have actually happened inside these forests,

a place of secrecy and ritual.

NARRATOR: Coming up, Nazi terror from the skies.

The men who survived had gone through a hellish ordeal.

NARRATOR: And a colossal code in the desert sands.

This is an incredible piece of U.S. History,

and you can see it from space.

NARRATOR: December 2020.

A satellite passing over the coastal city

of Tobruk in Libya captures this image.

MORGAN: Everything looks very arid,

but running right through the middle is this line.

Behind the line, are a series of these oval structures.

It looks like two eyes and a nose or a mouth,

perhaps -- it's really strange.

NARRATOR: Further analysis reveals something even stranger.

CAVELL: When we zoom out,

there are dozens of these structures

all over the landscape, and this zigzag line

actually continues in an arc around the entire city as well.

NARRATOR: Military records reveal the satellite has

captured the legacy of an extraordinary

sequence of events,

ones that took place here over 80 years ago.

HYMEL: It's amazing to think that these simple shapes in

the desert

had such an incredible importance to World War II

and world history.

NARRATOR: During World War II,

Tobruk is the only port in Eastern Libya

capable of harboring large military ships.

Between 1940 and 1943,

it plays a central role in the North Africa campaign,

a battle for domination of this region's

strategic and oil-rich sands.

CAVELL: Anyone who has control of the port of Tobruk

is gonna have control of the eastern Mediterranean.

If it's captured by an enemy,

it's gonna be very hard to get shipping

into the Suez Canal.

ALBERTSON: Tobruk was an extremely

strategically valuable city,

and both the British and the Germans wanted it.

NARRATOR: At the outbreak of the war,

Libya is an Italian colony.

To protect his prized asset from advancing Allied troops,

Mussolini surrounds the city with a 28-mile-long anti-tank

ditch and defensive positions.

What you're seeing in the image is actually

a defensive point for the Italians

constructed prior to the Allied invasion.

CAVELL: And then the ovals that we see,

they're actually strong points, artillery positions,

machine gun nests, and places where you can have

a number of infantrymen along the wall.

NARRATOR: On January 21st, 1941, the Allies'

36,000-strong Western Desert Force attacks Tobruk.

The Italian defensive forces, accustomed to fighting

smaller armies in colonized Africa, proved to be no match

for the battle-hardened Brits and Australians.

The Italians were really good at beating up on little kids.

That's a very coarse way of putting it,

but then, suddenly, they're in the war with the big boys.

[explosion blasts]

Despite the Italians' efforts,

it only takes the Allies 29 hours to breach these defenses

and occupy Tobruk.

NARRATOR: The loss of Tobruk infuriates Hitler.

To recapture the port, he unleashes the might of

the Africa Corps, led by the legendary military

tactician, Erwin Rommel.

ALBERTSON: Erwin Rommel was, perhaps, the greatest

armor commander in the German military,

and he was feared by many of the Allied commanders.

CAVELL: Rommel's siege of Tobruk is a ferocious operation.

It's mainly the Australians who are guarding

the city, and what they have to withstand --

it's pretty gruesome.

NARRATOR: For eight months,

Rommel's forces launch a series of brutal assaults

on Tobruk.

Yet using the line of defenses left by

the retreating Italians,

the Allies managed to repel the Nazi attacks.

The Australians actually take on the moniker of

the Rats of Tobruk, because they hang on,

they burrow in, and they don't let go.

They're under this constant threat that

the enemy is gonna break through.

They're air raided almost constantly.

So the men who survived the siege

of Tobruk had gone through a hellish ordeal.

CAVELL: It's this holding out of the garrison that really

turns the Rats of Tobruk into legends of World War II,

but it's this operation that also gives rise to

another legendary group

of military operators, and that, of course, is

the British SAS.

NARRATOR: The SAS, short for Special Air Service,

begins life three months into the siege of Tobruk

as L Detachment, a handpicked group of 65 soldiers.

The brainchild of Major David Stirling,

it will revolutionize the way war is waged.

What Stirling's doing here in the desert in Tobruk

during World War II is really

the birth of the special forces worldwide.

NARRATOR: Like the U.S. Navy Seals,

the SAS will become one of

the most feared and admired special forces on Earth,

elite warriors whose exploits are recorded in

the medals they earn and the blood they spill.

They took guys that were tired

of being collared in a regular unit.

They wanted action with the enemy, and you give them

the fuel, the vehicles, and the weapons to go out

and do it.

NARRATOR: Stirling tasks his elite soldiers with a series of

audacious raids to take out

Nazi-held positions and airfields.

These are men who are fearless, who are being dropped into very

dangerous positions behind enemy lines, where they're going

to commit acts of sabotage.

MORGAN: When you take people like that and give them

latitude to go accomplish a mission without

micromanaging them,

they can very often be capable of producing miracles.

NARRATOR: Throughout 1941, L Detachment destroys hundreds

of Rommel's aircraft, trucks, and trains,

helping to prevent the Nazi conquests of North Africa.

These British commandos conduct raids that are

so audacious and so fast that they become

these almost mythological warriors that

the Germans just don't know how to deal with.

CAVELL: David Stirling becomes a legend unto himself.

The Germans begin to call him the phantom major,

because he just appears and disappears,

seemingly without a trace.

NARRATOR: Eight decades after the city gave rise to

the legends of the Rats of Tobruk and the SAS,

Libya is once again a war zone,

the site and the image inaccessible to outsiders.

Yet evidence of the seismic role it

played in military history remains, revealed from space.

We can't go and walk on the battlefield the way that

we can Normandy, and so it's less familiar to us,

and it's a shame for that, because that is a place where,

in many ways, the outcome of World War II was decided.

NARRATOR: Coming up, death and riches

in the Nevada hills.

They find more than $100 million

in less than a decade.

NARRATOR: And a nuclear face-off in the Arctic.

You've essentially set the stage for World War III.

NARRATOR: November 2017.

480 miles above eastern Nevada,

an eye in the sky scans deserted scrubland below

and captures this image.

We're looking at kind of a hardscrabble landscape, but

then lined up perfectly is a series of silver circles.

It almost looks like six gigantic buttons

that you could push from space.

NARRATOR: The weird line of giant buttons

is over 200 feet long.

Analysts turned to Maxar's SecureWatch

technology to study them in more detail.

JOYCE: Look at the shadows -- because this

image was captured with a low sun elevation,

we can very clearly see this

cone shape with each of these objects.

NARRATOR: Each of the giant stone cones also has

a hole at its summit -- George Kourounis recognizes

the mystery structures.

KOUROUNIS: I think that these are charcoal kilns.

These kilns would typically be round or beehive-shaped,

so that's a smoking gun here

that tells me that this is exactly what we're looking at.

NARRATOR: Land registry documents reveal

that the kilns are a relic

of an incredible yet often overlooked period in

American history.

Records show that these structures are on the land of

Wards Mine,

which was a silver mining boom town.

RUBEN: Everyone's heard of the California Gold Rush,

but we sometimes forget that there was another big one.

There was the Nevada Silver Rush.

NARRATOR: The Nevada Silver Rush begins

in 1859, when vast reserves of

the metal are discovered in a remote canyon

in the west of the state.

RUBEN: The silver boom is kicked off by the discovery of

the Comstock Lode,

which is the richest deposit of silver ever found in

the western U.S.

NARRATOR: In California,

much of the gold is trapped in veins hidden deep inside

the mountains,

but at Comstock and elsewhere in Nevada, silver forms strictly

on the surface, in beds hundreds

of feet wide and over a mile long.

HYMEL: The Comstock mine on the border of Nevada is

the largest silver mine in

the United States and is really gonna be

the focal point of this silver boom.

They find an ore vein here that's worth more

than $100 million dollars in less than a decade.

HYMEL: The amount of money is mind-boggling.

It is a geyser of cash for anyone involved.

NARRATOR: Soon, more reserves are discovered across Nevada,

and by the 1870s,

20 percent of the world's silver originates from this state.

600 boom towns rise out of the desert soil,

including Ward, the site in the image.

When the word got out,

everyone rushed into that area, and they began prospecting.

If you could find the source, and you could claim it

for yourself,

you could become wealthy beyond your wildest dreams.

NARRATOR: Yet Nevada's riches also mean that many of its towns

descend into anarchic,

no-go zones, where murder and rape are commonplace.

MORGAN: The sudden appearance of vast numbers of people

means that you suddenly have problems with crime.

HORTON: The conditions there were lawless.

It was a very dangerous place to be,

and some people made their fortune, but many did not.

[gunshots blasting]

NARRATOR: During the 1860s, the violence unleashed

by the Silver Rush spreads nationwide,

when the state of Nevada sends 1,200 men

and $400 million dollars to aid the Union Army.

It makes a critical difference to the conflict

at a time when the Confederates are going bankrupt.

The discovery of silver in western Nevada doesn't

just enrich the few people who found it.

It finances the Union Army in the Civil War.

It helps build the city of San Francisco.

It leaves an imprint on financial markets for decades

to come.

NARRATOR: When word of the Silver Rush reaches Italy,

specialist charcoal burners called Carbonari head

to Nevada.

They erect the beehive-shaped ovens in the image

to extract yet more riches from the Nevada hills.

In order to purify silver from silver ore,

you need to heat it to very high temperatures.

PEPPER: This is an incredibly efficient way of

producing charcoal,

and it adds to the productivity of the mine.

NARRATOR: By 1879, the Ward mine,

like many others in Nevada, has exhausted its reserves,

and the Carbonaris' kilns grow cold.

Today, much of the former mining town is being reclaimed

by the desert, but the structures

seen from space remain as monuments to

the state's extraordinary Silver Rush years.

This is an incredible piece of U.S. mining history,

and luckily in Nevada,

the dryness has preserved it, and you can see it from space.

NARRATOR: Coming up, something big

and weird in Greenland.

I can't tell what they are, but there's hundreds of them.

NARRATOR: And the code of the cannibal warrior.

A successful warrior might eat his flesh and present

the head as a trophy to his chieftain.

NARRATOR: August 17th, 2020.

A satellite orbiting over

the Arctic scans a series of structures in

northwest Greenland.

MUNOZ: The runway and surrounding facilities

that are Thule Air Base,

and it's the northernmost base that

the Americans have in the entire world.

NARRATOR: As the spy bird moves southeast from the highly

clandestine facility,

it captures something that continues to baffle analysts.

It looks like a big claw or something

just took marks out of the ground.

It's really cut up, like

a knife has sliced through the territory.

It's bizarre.

NARRATOR: Scale analysis reveals the weird scars

cover an area of six square miles.

These are quite regular and definitely don't look natural.

I can't tell what they are, but there's hundreds of them.

Analysts study Thule's history for clues,

a history that begins in the late 1940s,

when growing Soviet aggression prompts the U.S.

to establish a military outpost in the Arctic.

MORGAN: Having a base in Greenland meant that the U.S.

had a last base of operation

where we can launch an attack before Soviet

intercontinental ballistic missiles reached us.

NARRATOR: Using the code name Operation Blue Jay,

planning for construction of the base begins in 1949.

MUNOZ: The construction of Thule Air Base

was probably one of the most complex

and difficult undertakings

by the U.S. military at the time.

Thule is a very, very difficult

place to build anything -- it's uninhabited,

so you have to bring in all the supplies -- concrete,

food, water, everything.

NARRATOR: In July 1951, 300,000 tons of materials arrive

in the Arctic on a flotilla of 120 ships.

Thick sea ice forces the military to use dynamite

to open up a safe passage to the site.

Yet when they arrive, engineers are

confronted with an even greater obstacle.

Permafrost up to 1,600 feet deep.

The first efforts to construct this

base really were not very successful.

They came unglued pretty quickly.

Pentagon planners did not realize

that the heat generated from

the building will essentially melt the soil, and the building

will sink into the ground.

NARRATOR: The threat of buildings sinking into

the thawing permafrost forces engineers to change

their construction plans.

I think there's a good possibility

that these are actually the foundations

of the original air base that was built in 1951.

NARRATOR: In the decade following

the base's construction, Thule becomes

a key staging point for Operation Chrome Dome.

Operation Chrome Dome is the idea that you

have nuclear armed B-52s in the sky

24 hours a day, ready to receive

an order to strike targets in Russia.

NARRATOR: One incident during one of

Operation Chrome Dome's clandestine missions

offers another possible explanation

for the weird marks in the image.

On January 21st, 1968, an American B-52

stratofortress crashed during

an approach to land at this airfield.

There's a cabin fire on the inside of the airplane.

The aircraft commander realizes that they can't

save the airplane and tells everybody to evacuate.

MORGAN: The crew bails out -- the aircraft

then belly flops and bursts into flames.

[explosion blasts]

NARRATOR: The incident claims the life

of one crew member,

but the U.S. military's problems have only just begun.

What the aircraft was carrying was four

B-28 thermonuclear bombs.

Once the plane actually made impact

on the ground, these weapons went off.

[explosion blasts]

NARRATOR: The nukes on the plane

have an explosive yield 400 times

greater than the one which destroyed Nagasaki

in World War II.

The incident threatens to dramatically

escalate hostilities between Washington and Moscow.

MUNOZ: You have this crazy kind of mix

of a catastrophic accident,

and tensions on both sides

during the height of the Cold War --

you've essentially set the stage for what could have

been World War III.

NARRATOR: Mercifully, a safety mechanism

prevents a full-scale nuclear explosion,

but the accident still releases vast amounts of

radioactive material across permafrost near the base.

MORGAN: An area of over three square miles

was completely contaminated by radiation.

The cleanup effort would go on for nine months.

It would involve 700 people

and would cost the American taxpayer $10 million.

Maybe the marks on the soil were caused when

the area had to be cleared out after this accident.

NARRATOR: Officially, the cleanup operation

took place to the north of the marks in the image.

But analysts learn the scars could still

be connected to the 1968 nuclear incident.

They didn't actually manage to get everything

in the cleanup operation -- declassified

information revealed that one of these bombs was never

recovered -- somewhere down there

under the ice in the ocean is an unrecovered nuclear weapon.

NARRATOR: A nuclear weapon lost under the Arctic ice.

Strange gashes in the landscape.

In this corner of Greenland,

the Cold War is far from over.

MORGAN: The entire area is subject to top secrecy.

And because of that, it's very,

very difficult to get any information about this base.

So we may never know what we're looking at in the photo.

NARRATOR: Coming up, the lost jungle civilization.

HEIMLER: There are these weird symbols,

and nobody knows what they're there for.

NARRATOR: September 2019.

A drone conducts an aerial survey

over the South Pacific Islands of Samoa.

As it scans the dense tropical forest,

it spots something nestled among the foliage.

HEIMLER: It almost looks like the stump of a giant tree

that has been cut off at its base.

However, this formation is massive.

It's not really obvious at all what this thing is.

Call me confused.

NARRATOR: Further studies reveal that there are around

80 of these giant shapes scattered across

the archipelago,

some thousands of years old.

They're these weird geometric symbols rising up out of

the dense jungle vegetation, and nobody knows

what they're there for.

NARRATOR: Experts delve into the island's history in search

of clues.

What makes this

an especially tricky problem is that the Samoans

traditionally did not have a written language.

This is what's called a memory society, because their stories

and their legends and their histories

were all passed down orally.

NARRATOR: Studies suggest the first star mounds appear

soon after Polynesians arrive in Samoa in around 1,000 B.C.,

having somehow found the island's concealed

in millions of miles of open ocean.

JANULIS: Not a lot is known about the earliest seafarers

that settled Samoa,

but these people colonize almost every island in

the Pacific in a very short amount of time.

One of the more interesting things is they look somewhat

like rays of stars spanning out,

and the Pacific Islanders certainly followed the stars at

night when they'd go across vast expanses of water.

NARRATOR: The seafarers believe in many gods and goddesses,

heroes, and demons.

Some analysts speculate the star shapes could also have

been built to honor the celestial deities

that guided the Polynesians to their new lands.

There's definitely a sort of

symbolic or ritualistic aspect to these.

They're repeating the same shape in uninhabited

parts of very hard to reach places.

NARRATOR: According to Samoan beliefs,

people, spirits, and objects are endowed with a life force

called mana.

As the island's population grows,

it fuels a series of conflicts between tribes hoping to

acquire this supernatural power from their enemies.

JANULIS: Being a warrior was important.

It was something expected of you,

and if you hadn't ever gone to war,

you probably didn't have a lot of respect from your peers.

NARRATOR: The pursuit of mana would sometimes lead to

victorious warriors indulging in gruesome

post-battle rituals.

So a successful warrior might cut the head off of his enemy,

eat his flesh, drink his blood,

and present the heart as a trophy to his chieftain.

By doing so,

they thought that some of the courage and bravery

that was in that soldier would

transfer into them by virtue of eating.

Given Polynesia's tribal history,

it's entirely feasible that these are defensible

fortifications that individual

clans would have retreated to.

NARRATOR: Yet when local archaeologists

begin excavating the shapes revealed from the skies,

they discover something incredible.

It turns out Samoa has a lot more structures on

it under the dense jungle vegetation

than we previously assumed.

BELLINGER: These star mounds are actually just part of

a much broader residential complex that stretches

for acres and acres.

NARRATOR: It appears that the island's dense jungle

conceals a series of megastructures, lost to history.

This shows that we have greatly underestimated how

complex and large scale

the Samoan society was before the Europeans

contacted them.

NARRATOR: European explorers arrive in Samoa

in the early 18th century.

Death comes with them, and over the next 200 years,

a series of epidemics sweep the islands.

Populations that have no contact

with European population for thousands of

years have no immunity to our diseases.

When the Europeans finally got to know the Samoan culture

and people, they were seeing

the remnants of a plague apocalypse.

NARRATOR: Previous studies suggest European diseases

killed around one in five Samoans.

But the scale of the structures hidden by

the jungle canopy reveals

the catastrophic effect of European contact was much

greater than previously feared.

This new evidence shows us that the Samoans were not

a tiny population at the time

the Europeans arrived, and that many,

many more aboriginal Samoans died as a result

of colonization.

NARRATOR: The structures are both a tribute

to the extraordinary civilization

that once thrived here and a record of its sad demise.

We're only beginning to scratch the surface

of this mysterious and enigmatic culture,

and these star mounds may hold part of the mystery.