Original subtitles

NARRATOR: They're watching you.

More than 6,000 satellites circle the Earth.

Every day, they uncover new, mysterious phenomena

that defy explanation.

Revealed from the skies,

the 3,000-year-old code of the disappeared.

We have to use these structures to

tell the story about how they lived.

NARRATOR: The mystery of the Pennsylvania Terrordome.

What it did was drive people crazy.

NARRATOR: And Kim Jong's secret animal assassins.

They'd swim up to an enemy vessel, and then...

bang!

NARRATOR: Baffling phenomena, mysteries from space.

What on Earth are they?

Sardinia,

the second largest island in the Mediterranean.

Kathleen Nicoll is venturing deep into

this 9,000-square-mile land mass,

lured by something strange captured from the skies.

I'm on my way to investigate a large feature,

and it looks like it's a castle,

but it's like no other castle I've seen before.

NARRATOR: The image, captured on September 27th, 2021,

reveals a strangely-shaped structure located in

the island's arid interior.

This is a really intriguing-looking image.

We've got in the center what seems

to be a triangular tower, then within it there's this kind of

keyhole-type structure.

This is really very unusual.

I've never seen anything like it anywhere else in the world.

NARRATOR: A scan of the wider area deepens the mystery.

NARDI: The island of Sardinia is littered

with these stone structures.

There are literally thousands of them

scattered throughout the island.

NARRATOR: In total, more than 7,000

towering edifices are found here.

Locals call them nuraghi, and they're relics of

an ancient civilization whose origins and fate

are shrouded in mystery.

AUERBACH: It's inherently difficult to reconstruct

their lives and their culture,

because they didn't leave written records.

NICOLL: We don't know much about these people,

so we have to use these structures to tell the story

about who these people were and how they lived.

NARRATOR: The Nuragic civilization emerges from

this island around 1800 BCE.

Over the following 1,500 years,

they build more than 20,000 of these structures,

a third of which survive to this day.

Today, Nicoll is heading to one

concealed in the center of the island.

Wow.

That's something.

It's actually breathtaking.

NARRATOR: The crumbling structure sits

on the summit of a 2,500-foot-high hill

and commands views of a large region of the countryside.

As Nicoll explores the central towers,

she discovers their walls are 10 feet thick.

NICOLL: This is incredibly impressive.

This wall that I'm standing on is basically three layers deep.

It has limestone layers that are built in upon themselves.

NARRATOR: The structure and others like it

were built during the Bronze Age.

What sets the Nuragic people apart is that during this time

most other tribes were constructing basic settlements

fashioned from mud or wood.

The Nuragics were master stonemasons,

and they created these structures without any mortar.

Considering that this is a civilization that is

4,000 years old,

that's -- that's really quite impressive.

HUNT: These are sophisticated buildings.

They're the vanguard of high civilization.

NARRATOR: In the past,

a number of the towers were more than 100 feet in height,

making them some of the tallest prehistoric

structures in Europe,

yet to this day, their purpose remains unclear.

Nobody knows exactly for certain,

but the most likely explanation is that

they're kind of like mini castles,

each with its own little territory around it.

NARRATOR: When the nuraghi are built,

Europe is undergoing a period of great upheaval

and extreme violence.

Civilizations are swapping tools and weapons made

from stone with ones fashioned from metal.

At first, this transition brings

great prosperity to the Nuragic civilization.

It seems that Sardinia was a place of incredible wealth.

The reason for that was minerals.

AUERBACH: In terms of natural resources,

this is quite a rich island.

You have copper and tin, which means that they could

make bronze.

NARRATOR: Over the years, the Nuragic people

become expert miners and metal workers.

Word of their skills in bronze making

spreads throughout Europe.

The Nuragics established significant trading

partnerships, and there is some

evidence of metals being traded as far away

as Scandinavia.

[battle noises]

NARRATOR: Yet as their wealth grows,

the Nuragic become the targets for foreign powers

looking to exploit their mineral-rich lands.

HORTON: When a society controls valuable commodities,

the civilizations around the Mediterranean look jealously

upon it and want to control it for themselves.

It's a time when people were trying to control the landscape,

so this could be a fortified tower.

NARRATOR: Other experts favor different theories,

speculating that the structures were

used as temples or observatories.

We still are reaching out to try to understand,

because the real purpose of these towers

is a mystery to this day.

NARRATOR: What is known is that at some point

during the Nuragic reign, a mystery event hit Sardinia.

Something bad happened.

Whether it was a snowballing of effects

or whether it was one sudden cataclysm,

the builders of the nuraghis

in Sardinia took a pause.

NARRATOR: What's more, this event has been linked to

one of the most enduring mysteries of antiquity.

Some have advanced the idea that

the Nuragic civilization was the inspiration for Atlantis.

NARRATOR: Coming up -- tsunamis,

Atlantis, and the fall of Egypt.

We do know what happened was inconceivably destructive.

NARRATOR: And the island of the dead.

It's bizarre -- I mean, this looks like the island's

been hit by a giant shotgun round from outer space.

NARRATOR: Drawn by mystery ancient structures

revealed from the skies,

Kathleen Nicoll is on the Mediterranean island

of Sardinia.

Wow, look at that.

NARRATOR: The structures, called nuraghi, are the relics

of a civilization that suffered a mysterious decline

in the 12th century BCE.

One of the possible reference points

for the decline is the legend of Atlantis,

the city buried beneath the waves.

The Greek philosopher Plato documents the story

of Atlantis in around 360 BCE.

He writes that, like the Nuragic people,

it was a highly advanced civilization whose island is

filled with gates and towers.

After becoming greedy and morally bankrupt,

the gods punish it with a cataclysmic event.

HORTON: The myth of Atlantis has been

a matter of great archaeological and historical debate.

NARDI: So Plato actually wrote that there was an island

that succumbed to a massive

marine disaster and was destroyed in a night and a day.

NARRATOR: The theory goes that in the 12th century BCE,

a similar event engulfed Sardinia,

a celestial catastrophe that destroyed many nuraghi

and gave rise to the legend of Atlantis.

Some people have suggested a meteorite coming onto water

and creating a large tsunami

could generate enough force to impact the coast.

HUNT: If you had a big meteor land in the water

near the island, yeah, it could create tsunamis.

There's no question.

NARRATOR: If a giant wave did once hit Sardinia,

it would likely have engulfed the low-lying southern part of

the island.

But Nicoll doubts this is evidence

of the annihilation described by Plato.

Most of the nuraghi in Sardinia are in mountaintop areas.

So even if a tsunami came in,

it probably wouldn't have completely killed off

the Nuragic people.

NARRATOR: Nicoll heads inland, searching for more clues

that could shed light

on the fate of the Nuragic civilization.

Wow.

This is really incredible.

I can see

a triangle surrounded by a circular court,

and the shape is what you think of as a keyhole structure.

NARRATOR: The keyhole entrance guides the geographer down

towards what appears to be a well.

The walls are getting narrower as I go down.

This whole place is designed to draw you into the center.

I can definitely conclude

that this is a sacred place.

NARRATOR: Historians speculate that this well

was a kind of subterranean temple,

a place used for ceremonial worship for many centuries.

Archaeologists found some very unusual bronze figurines under

the water in the well,

which leads us to believe that they were some sort of offering

or a way of asking for assistance from the water gods.

There are cultic associations

with water in Sardinia.

There are goddesses and gods of springs and water.

NARRATOR: Such was the importance of water

to the people here that they construct

40 similar aqueduct temples across the island.

It would appear that ritualized activities

take place within them,

because without water, you can't have life.

NICOLL: Sardinia does not get very much water,

and it is drought-prone,

so coming here has deep significance.

NARRATOR: Like the towers dotting the island,

it is uncertain what took place within this temple.

But the Nuragics' deep connection with water

and the ocean could shed more light

on why they stopped building their remarkable

stone structures three millennia ago.

What is interesting is that in Sardinia

at around the same time, we see that

many of the sites are being abandoned, and this

might well be connected to the Sea Peoples

in the ancient texts.

NARRATOR: The Sea Peoples are mysterious groups

of naval raiders who begin

attacking different Mediterranean civilizations

around 1200 BCE.

Some historians speculate they originated from Sardinia.

The Sea Peoples are recorded in both Egyptian

and the Mycenaean history and seem to

have had a massive impact on both civilizations --

destroyed their towns and palaces and so forth.

Egyptian inscriptions reveal that pharaoh Ramesses III

battles the Sea Peoples in around 1177 BCE.

Some of the invaders are called Shardana,

a possible ancient name for Sardinia.

There were whole migrations of peoples,

and many of them went to invade Egypt.

NARRATOR: Whether the Nuragic people sailed from Sardinia

to conquer and occupy other lands remains unclear.

But over the following centuries,

their civilization begins to disintegrate

and ultimately disappears from history.

NICOLL: We're not exactly sure what happened to this people.

What's certain is that the Nuragic civilization was

an amazing, amazing culture

NARRATOR: Today, all that remains of

these extraordinary people are these strange codes

wrought in stone and visible from the skies.

AUERBACH: When you think about it,

this is a culture that lasted for more than 1,000 years,

and it's really quite impressive.

NARRATOR: Coming up, inside the chamber of horrors.

It's really shocking to think that

this was allowed to happen on U.S. soil.

NARRATOR: And the disappearing ghost fleet.

These ships vanish completely.

NARRATOR: July 30th, 2019,

a satellite flying over the eastern

United States spots something abnormal

in the Philadelphia suburbs.

What we see are 10 large individual spokes,

all jutting out of a central circular point.

So weird, because you have

this whole urban area, and then all

of a sudden, here in the middle of it,

there's this strange structure.

NARRATOR: The mystery edifice measures

around 1,000 feet in diameter.

I mean, it's huge, but you couldn't really guess

just from looking at it what this structure is for.

NARRATOR: To some, the structure's shape suggests

it could be a relic of a defining time

in 19th century history.

These spokes radiating out are reminiscent of

a railroad roundhouse with a rail turntable at its center.

NARRATOR: In the 1860s, Philadelphia is

a major hub of America's fastest-growing

railroad network.

Many of the 230-ton locomotives

have trouble backing up,

necessitating the introduction of special rotating platforms.

AUERBACH: These were really a game-changing

piece of technology,

incredibly space-saving and time-saving, too,

and they became standard pieces of equipment across

the industrialized world.

NARRATOR: To others, the presence of a wall

around the structure indicates

that it dates from a much darker time

in this city's history.

There's a good chance that these walls

are here to keep people in.

I believe this is the notorious Holmesburg Prison.

NARRATOR: Local records confirm that Holmesburg

opened at this site in 1896.

It represents an attempt to revolutionize

the U.S. penal system.

Before Holmesburg, prisons were more like dorms.

There were these big, open structures where people

could mix.

RODRIGUEZ McROBBIE: Prisons were more or less these sort of

open stews, where prisoners of

all different crimes were lumped together.

The conditions were unsanitary.

They were really not pleasant places to be.

NARRATOR: Unlike traditional prisons,

Holmesburg's layout means that guards in a central hub

can monitor the 600 cells at all times.

Designed by evangelical Quakers,

the isolation of the inmates is

meant to encourage penitence and remorse.

This new system was intended to give

people individual rooms to think about their crimes,

but unfortunately, what it basically did

was just kind of drive people crazy.

NARRATOR: Studies reveal that such isolation leads to spikes

in psychosis and other mental disorders among prisoners.

RODRIGUEZ McROBBIE: Part of the problem came from

a sort of imperfect understanding of human nature,

one of those things being that people

do need to be around other people.

NARRATOR: What's more, many of Holmesburg's inmates are

violent criminals,

meaning riots, bloody beatings, and killings are commonplace.

And in the 1950s, their suffering steps up a gear,

when authorities hire dermatologist,

Dr. Albert Kligman to treat skin conditions among the prisoners.

But when Kligman gets a view of these facilities

and its occupants, he has some other ideas

about how they could be utilized.

RUBEN: When Dr. Kligman sees the inmates,

he's quoted as saying that he sees acres of skin

on which he can conduct his medical experiments.

NARRATOR: Outside of prison, Kligman works for

pharmaceutical companies.

After embedding himself at Holmesburg,

he begins to test unlicensed medical products on the inmates

in exchange for money.

These tests help the facility

gain the nickname the Terrordome.

There are regular reports of inmates' hair and teeth

falling out, and bandages conceal evidence of

chemical burns.

SPICER RICE: He's turning these human beings into animals.

The pain that he's inflicting upon these people is immense.

RUBEN: Kligman gives the inmates herpes and staph infections

in order to look for treatments.

He even administers radioactive isotopes.

NARRATOR: Between 1951 and 1974,

Kligman experiments on thousands of inmates.

In one study, around 70 are exposed to large amounts

of dioxin,

the highly poisonous component of Agent Orange.

Many of these men were left

with lifelong debilitating health conditions.

In fact, to this day, it's said that you can recognize

a Holmesburg prisoner because of

the distinctive scars from skin burns and patch tests.

It's really shocking to think that this

was not just allowed to happen on U.S. soil,

but encouraged and funded by U.S. companies.

NARRATOR: A series of lawsuits finally brings

the brutal experiments to an end in 1974.

But despite public outcry, Kligman escapes sanction.

In the end, nothing happened to him really.

I mean, he died when he was 93 years old, and in many cases,

revered for discoveries that he made.

We still use chemicals that he developed by testing them on

these prisoners many years ago.

NARRATOR: Officials finally decommission Holmesburg in 1995.

Despite calls for demolition,

the haunting facility still stands,

a stain on U.S. history, visible from space.

For many, this is a disturbing

and harrowing reminder of some of

the more frightening parts of our past.

Coming up, Kim Jong Un's secret subsea assassins.

We're talking about a power-crazed despot.

So we've got to be extremely vigilant.

NARRATOR: And the 100-square-mile cipher.

The dead were so numerous that they were

stacked up in layers.

NARRATOR: November 4th, 2021.

Satellites keeping a watchful eye over

North Korea identify an unfamiliar object

in a river below.

There's some very unusual manmade structure floating out

in the river, maybe anchored in the river.

It looks like there's five hexagons that are all connected

to each other, and then they're also connected to the mainland.

It looks like a strange structure.

NARRATOR: At 30 feet wide,

each of the shapes appear to be

enclosures for fish or other aquatic animals.

Yet the structure's location puzzles analysts.

KOUROUNIS: There are naval units located

in close proximity to this structure,

so that makes me wonder if somehow the North Korean

military is involved in whatever is going on here.

NARRATOR: Analysts turned to Maxar's

SecureWatch technology for more clues.

It turns out the structure bears a striking resemblance to

one used by the Russian military some 4,500 miles away.

These hexagon shapes look very similar

to this facility on the Black Sea.

This facility is known for training dolphins, and this same

hexagon shape is the pen where the dolphins are kept.

These sites in North Korea

could be where dolphins are trained for military purposes.

NARRATOR: Over the past few decades,

dolphins have been used by several military superpowers

for highly clandestine missions.

The satellite image appears to be

evidence that North Korea is following suit.

There's one thing you can rely on, is that no matter how dire

and perilous the state of North Korea's economy is,

its leader will always ensure that its weapons

technology grows.

The use of dolphins in naval missions begins in 1960,

when U.S. researchers study the animals to streamline

torpedo design.

But they soon realize that the highly intelligent mammals

can play a much more direct role in warfare.

The U.S. Navy has conducted a lot of research

and experimentation using dolphins for non-combat roles,

to sort of achieved tactical and operational

objectives that simply can't be done by humans.

NARRATOR: In the first open sea exercises,

a dolphin named Tuffy successfully relays equipment

to divers 200 feet below the surface.

In further tests, the Navy uses

the mammals to detect and identify underwater explosives.

Their sonar is extremely sensitive, and it gives them

an acoustic picture of what the environment looks like.

This allows them to travel through murky waters

and locate mines on the sea floor or at the surface.

NARRATOR: In response, the Soviets also

begin assembling units of military dolphins.

Former Communist dolphin trainers claim the mammals

were kept in small, isolated pens,

like the ones seen in North Korea

and deprived of food to make them reliant on their handlers.

MUNOZ: The Russians actually tried

to weaponize these animals,

trying to use dolphins as a method of carrying

either munitions or bombs and using them to

attack adversaries

in actual combat operations.

WALTERS: They'd swim up to an enemy vessel,

rub against the keel, and then...

bang goes the dolphin and the target.

NARRATOR: In more recent years, Russian dolphins have

been trained to carry out stealthier missions.

Fitted with a lethal gas-filled needle,

they patrol Russian naval facilities to

track down and inject enemy divers.

As far as we can tell, these troubling

dolphin training programs are still up and running.

If anything, they're probably more advanced

and secretive than they were before.

If North Korea is acquiring and training the animals,

that is a real cause for concern.

NARRATOR: North Korea possesses 40 nuclear weapons,

which can be launched from submarines.

The fear is that Kim Jong Un will use

these animals to prevent Western nations from monitoring

their deployment.

Historically, Kim Jong Un has

been deeply mistrustful of foreign powers.

So he could have trained dolphins to try to take out

any vessels or divers that could have come close

to his nuclear arsenal.

NARRATOR: North Korea has a history of

such preemptive strikes against naval adversaries.

In 2010, a mysterious blast sinks

the South Korean Navy ship Cheonan, killing 46 sailors.

The facility is seen from space could represent

an unusual and worrying escalation in tensions

with Kim Jong Un's regime.

We're talking about a totalitarian state,

and it's ruled by this kind of power-crazed despot.

So we've got to be extremely vigilant about North Korea.

NARRATOR: Coming up,

the 400-foot-long floating skeletons.

You'll have the predators come in and strip it

down to its bones.

NARRATOR: And attack of the cannibal army.

MUNOZ: I mean, can you imagine?

It's like something out of a nightmare.

NARRATOR: May 29th, 2020.

Satellites wheeling over the West African

city of Nouadhibou

scan the coastal waters below.

At first glance, it doesn't seem that strange,

a bunch of ships off the shore,

except I'm not seeing any wakes behind them.

These ships don't seem to be moving, and a lot of

them don't look like they're in a very good state of repair.

NARRATOR: Historic images confirm around 300 vessels,

many of them hundreds of feet long,

have lain abandoned for years or run aground.

The fact that they're just sitting here idly is

pretty puzzling.

RUBEN: Ships can cost millions of dollars.

It's strange that all these vessels would

just be left there to rust.

NARRATOR: Nautical records reveal that the ghost fleet

is the legacy of a saga

of corruption that has blighted this city for decades.

Unfortunately, over the years,

Nouadhibou has become the world's largest

ship graveyard.

This is basically a time capsule

of rusting vessels from across the globe.

NARRATOR: Globally, shipyards break up around

800 large vessels each year.

The biggest facilities strip up to 10 million tons of

steel annually,

166 times the amount found in the Empire State Building.

Just because a ship is decrepit and rusted

and derelict doesn't mean that

it doesn't have tremendous value in the raw resources

that are still there.

RUBEN: Everything that can be salvaged will be salvaged.

These ships vanish completely.

NARRATOR: Ship breaking can generate billions of dollars for

yard owners.

The potential for vast riches means

there's a dark side to the industry.

Until about the late 20th century,

these scrapyards would typically be in cities

in industrialized nations,

but with labor being very inexpensive in certain

countries and the cost of steel going up,

it's been more economical for these shipbreaking yards to be

in places like Africa and Bangladesh.

Work in these shipbreaking yards is incredibly dangerous

and is usually performed by migrant workers

who have no choice but to work in these unsafe conditions

or face hunger and homelessness.

NARRATOR: In some yards, exploitation is rife.

There are no safety regulations,

and children account for up to 20 percent of the workforce.

It's not uncommon for these workers to have all kinds

of injuries, from being crushed

by equipment to broken limbs to

burns from their blowtorches, you name it.

NARRATOR: Since 2009, more than 400 people have

died while dismantling vessels in these yards.

Other workers face different but equally horrific fates.

Even if these workers leave the job site alive,

they're still in contact with so much hazardous waste that

they can be made sick by what they work on.

RODRIGUEZ McROBBIE: People who work in these places

often succumb to horrible cancers or even diseases like

asbestosis later on in life.

NARRATOR: Despite the toxic, perilous conditions

at these yards, owners must pay large sums

to have their vessels dismantled there.

This has lured ships to end their days at the site

in the image.

It's really expensive to dismantle the ship properly

if you want to do it.

Many owners of these vessels simply can't be bothered.

The solution -- dump them here.

Countries like Mauritania have very depressed economies.

Money is hard to come by.

So it can be very tempting for these officials to take

these bribes to basically

allow their waters to become a dumping

ground for these ships.

NARRATOR: Over the past 40 years,

Nouadhibou has become the global center

for illegal shipbreaking.

Once dumped in the bay,

each vessel is scavenged by swarms of workers

and every morsel sold for profit.

There's value not just in the raw steel, but in things

like the fittings, the windows,

the cutlery, the life preservers.

This totally reminds me of

a carcass left in the woods to decompose.

You'll have the predators come in and strip it

down to its bones, and eventually,

there'll be nothing left.

NARRATOR: As the ships are picked apart,

they release a toxic cocktail

of carcinogens and heavy metals.

These ships are often smeared with paint and oils that seep

out into the ocean, polluting the ecosystem

and harming local wildlife.

The waters around here have become so noxious that

they can change the sex of local sea creatures.

Untold amounts of oil leak from rusting tankers,

polluting local beaches and bays.

At first, abandoning these vessels seems like

a victimless crime,

but in the long run, all of these toxins ending up in

the environment becomes a real ecological catastrophe.

NARRATOR: While officials continue to line their pockets,

those who live here will keep paying with their lives.

The legacy of the abandonment of these ships

is going to last for generations.

NARRATOR: Coming up,

death in paradise.

Something pretty horrific happened here

on the sleepy island of Tonga.

NARRATOR: June 27th, 2020.

Aerial archaeologists study the Pacific archipelago

of Tonga.

As they analyze Lidar scans of the island of Tongatapu,

they spot something strange

hidden beneath the forest canopy.

CAVELL: You see these weird circular marks all over

the island, and there are thousands of them.

AUERBACH: It's bizarre -- I mean, this Lidar scan makes it

look like the island's been hit by a giant shotgun round

from outer space.

NARRATOR: Around 10,000 circular shapes litter the land mass,

relics, some suspect, of a wave of

violence that swept these islands eight decades ago.

WALTERS: The Lidar scan,

if you look at it, your mind turns to

one thing -- bombs -- and that, of course, means war.

ANNOUNCER: The crime of the century.

NARRATOR: In January 1942,

following the attack on Pearl Harbor,

Japan sets its sights on several strategically vital

South Pacific Islands.

The Second World War was actually the world's first

truly global conflict, and as a result,

it even makes its way to the relative obscurity of Tonga.

[gunfire blasting]

NARRATOR: As Japanese forces sweep towards the islands,

the U.S. launches a counteroffensive.

In May 1942,

the two nations face off in the Battle of the Coral Sea.

The engagement sees Japan capture territory in

New Guinea and the Solomon Islands,

while U.S. forces seize Tonga.

Tonga's main island became

a major transport hub for the Allied shipping lanes.

It was key to the U.S. strategy in the Pacific theater.

NARRATOR: What's puzzling about the image is that America's

8,000-strong occupying force

ensures Tonga emerges unscathed from the war.

It appears that the American military occupation

functioned as a deterrent,

because the Japanese never attacked the island.

And that produces a bigger question -- if warfare

never came to Tonga during World War II,

what are all these pockmarks?

NARRATOR: Studying the image in more detail gives

a new perspective on the strange circles.

AUERBACH: When you look a little bit closer,

you see that these are not concave.

They're actually convex.

They are small mounds or raised bits of earth.

What these look like to me are burial mounds.

NARRATOR: Archaeological examinations confirm

the presence of cadavers in the mounds.

Some contain over 100 bodies and appear

to have been used for internment for centuries.

They're actually constructed over an extraordinarily long

period of time, and the fact that these mounds are spread

evenly all over the island suggests that what we are

seeing here is some sort of ritual burial practice.

When European explorers first visit Tonga in the 1600s,

they find an island divided between rivaling chiefdoms.

The tribes use the mounds in the image to bury their dead,

but analysis of the distribution of

the graves uncovers a strange anomaly.

What we see on the eastern part of the island is an area

that was relatively underpopulated,

and yet there are a huge number of

these mounds in the region.

AUERBACH: There are a staggering number of them,

which means something pretty horrific happened here on

the sleepy island of Tonga.

NARRATOR: Accounts from missionaries who visited

the island could help explain the mystery.

There's a clue as to why so many deaths appear to have

taken place in just

one part of the island, and that comes from this really

bloody chapter in the island's history --

the battle of Poha.

NARRATOR: At the turn of the 19th century,

Tonga is gripped by a civil war

between its most powerful chiefs.

In the year 1801, the warlord Vaha'i

moves his warriors eastwards across the island,

intent on attacking his rival.

The reason for the western chief invading was that

the eastern tribes

had been involved in the assassination

of the Tongan king.

The chief Vaha'i was on a revenge mission,

and he was not taking any prisoners.

MUNOZ: People were massacred left and right.

The dead were so numerous that they were

laid up across each other in large piles.

There are also accounts that go a step further that discuss

the creation of great pyres,

where bodies of the slain were roasted, with the implication

being that cannibalism happened afterwards.

NARRATOR: After being piled high in mounds all over

the battlefield,

the slain are claimed by the earth.

MUNOZ: The extreme death toll suffered in the east of

the island could explain why the area has more mounds

than elsewhere.

NARRATOR: Over the following centuries,

the warriors' tombs are covered in vegetation,

only to be revealed once more from the skies.

These burial mounds show us that no part in human history

is free from evidence of man's capability

of violence and cruelty.

Man is truly wolf unto man.