Original subtitles

Mysteries can be buried anywhere.

Under the earth,

beneath the sea,

or even right under our own feet.

And when we stumble upon them,

sometimes, what we find can change history.

Tonight, big discoveries.

From a monumental secret buried beneath a basement...

Behind the wall, there's a cavity,

not an old cellar, but a tunnel.

This sprawling maze spans over 170 square miles.

It's a mind-boggling discovery.

To a massive ancient structure...

Archeologists realize it dates back

to a mysterious civilization.

Little is known about this culture

because almost nothing has been found

from the time of their reign.

Until now.

To a monster of epic proportions.

They uncover three feet of it, four feet of it.

Ultimately, it's 10 feet long.

Join us now, because nothing stays hidden forever.

It's 1927.

Charles Lindbergh is fresh off

his historic solo flight across the Atlantic.

It's the first of its kind.

It took him 33 hours to complete.

Now a global celebrity,

he heads out on a two-month goodwill tour

through Central America.

He flies solo, location to location,

and basically shakes hands with locals

and basks in his newfound fame.

One day he's flying,

he's crossing over this thick jungle in Honduras,

and something weird catches his eye,

something that doesn't look quite natural.

These structures poking through the gaps in the canopy.

To Lindbergh, it looks like this might be a city.

For centuries, rumors swirled

of a jungle settlement overflowing with riches.

They call it La Ciudad Blanca, The White City.

Now, Lindbergh's sighting reignites the search to find it.

Explorers, archeologists,

and treasure hunters set out on new expeditions

searching for the city Lindbergh claims he saw.

But even after several decades,

nobody finds a trace of the city.

Eventually, in 2012,

an explorer named Steve Elkins

tries to follow in Lindbergh's footsteps.

This time he's not looking out the window,

he's using LiDAR from the air

to see what the jungle below might be hiding.

Over the course of five days, Elkins and a small team

fly over this rugged terrain of the Honduran rainforest,

mapping the invisible.

On the final day, they process the LiDAR data,

and it seems to reveal what looked like the outline

of multiple man-made geometric structures.

Armed with the coordinates,

Elkins and his team head deep into the jungle

for a closer look.

They cut paths, encounter pit vipers,

and even flesh-eating parasites.

But despite all the hells of the jungle, they keep going.

After several weeks, the journey proves worth it

when they find the area pinpointed by their LiDAR scans

and they find something incredible.

There are hundreds of artifacts

arranged almost as if they were abandoned mid-ceremony.

These are the remnants of an unknown culture.

The scientists estimate they were built

somewhere between 1,000 and 1,500 AD.

As the group presses further into the site,

they come across something even more incredible.

At the heart of it all, they find a massive pyramid

half buried under the ground.

And it's just the tip of the iceberg.

There are mounds, pillars, plazas

stretching wide beneath the vines.

This wasn't a small mountain village,

this was a metropolis

that flourished before European contact.

The team recovered over 190 artifacts,

including a carved head of a part-human, part-jaguar.

They renamed the area of the site Valley of the Jaguar.

Excavations continue to this day.

And the site is deemed so valuable,

that the Honduran military now protects it.

To date, they haven't found

any huge cache of gold or treasure.

But there's a lot of excavating still to be done.

The recovered artifacts are now housed

in the Ciudad Blanca Research Center,

which focuses on the preservation

of the archeology and culture of the site

along with the wildlife that surrounds it.

You don't always have to go off the grid

to make amazing discoveries.

Sometimes, a big find is just beneath your feet.

In 1480, a boy is playing under the Italian pines

on Esquiline Hill in the heart of Rome.

As he runs along the slope,

his foot slips along a crack in the soil.

He leans down, peers into the opening,

and sees something that shouldn't be there.

He crawls through the gap,

and he finds himself in this hidden chamber.

Low ceilings, curved walls.

And when the boy looks up,

he notices that on the ceilings

are these very detailed frescoes.

There are mythological scenes, strange creatures,

and elaborate floral patterns covering the domed roof.

Soon, his discovery attracts

some of the era's most famous artists.

Artists like Michelangelo and Raphael

lowered themselves down

and explored the subterranean passages by torch light,

looking at all these

mythological paintings on the walls

to get inspiration for their own art.

But the site's purpose remains a mystery for centuries,

until a full-scale excavation of the area is ordered

in the mid-1700s.

Archeologists soon find other enormous rooms,

some up to 100 feet deep, covered in elaborate artwork.

As they explore the frescoes and the opulent rooms,

they start to put the pieces together.

They realize that this is a palace,

and it's a palace that matches the description

of one that was built in the First Century AD.

It's the Domus Aurea,

better known as the Golden House,

built by infamous Roman emperor, Nero.

Nero ruled Rome for 14 years in the First Century AD.

He's known for his extravagance, his cruelty,

his persecution of Jews and Christians,

for murdering his mother,

and for his very literal desire

to burn down the city of Rome to recraft it in his image.

So when a massive fire

destroys much of Rome in 64 AD,

many believed that Nero started it himself on purpose

so that he could build an opulent palace.

That new palace, the Domus Aurea, is huge.

It sprawls over 300 acres, has over 100 rooms,

marble walls, rotating dining rooms, detailed frescoes,

and perfume-dispensing ceilings.

There's an artificial lake surrounded by gardens.

And of course, at the center of it all

is a gorgeous golden statue of Nero himself.

It is 100 feet tall.

But before Nero can move into his new palace,

he's declared a public enemy by the Senate.

Even Nero's own guards abandoned him.

So he decides to take his own life,

and he stabs himself in the throat with a dagger

before he can be executed.

Once he's gone, Romans try to erase

all evidence that he even existed.

That includes his lavish estate,

which is torn down and buried.

Years later, another iconic structure is built in its place,

the Colosseum.

Then over time, the site is completely forgotten about.

Until centuries later,

when a young boy slips in the dirt.

It's just another day at sea for a group of fishermen,

until they haul in their nets

and find a lot more than just dinner.

It's September of 1931, and a British fishing trawler

is making its way up the North Sea.

It's just an ordinary day when, all of a sudden,

the nets come up heavy.

Excited at the possibility of a big catch,

the crew pulls the nets aboard

and begins looking through their haul.

The skipper, Pilgrim Lockwood,

notices a huge lump of peat tangled up with their catch.

He goes to break it apart with his shovel.

But as he does,

the shovel clangs against something solid.

At first glance, it looks like a chunk of bone.

But it's a darker color, and it looks carved,

and on one side it has what looks like

serrated, jagged teeth.

Whatever it is, it doesn't look natural.

The skipper sends his strange find

to the British Museum for more insight.

The researchers examine the object,

and realize that it's a prehistoric weapon

that's carved out of red deer antler.

It would've been lashed end to end with another antler

and used as a harpoon.

Researchers date the tool to the late Mesolithic Era,

sometime between 10,000 and 4,000 BC.

Everything seems to check out,

except for the fact that it was found so far out

and so deep underwater.

Mesolithic people were skilled hunters

with sophisticated tools like this harpoon.

But they were not skilled mariners.

They had no way of venturing far from shore.

That's when archeologist Grahame Clark

proposes a radical theory.

Maybe that spot in the North Sea used to be dry land.

Up to now, everyone had assumed

that there had always been a sea

between Great Britain and Continental Europe.

But Clark suggests, maybe that's wrong.

Maybe, thousands of years ago, this was land.

The following year,

a test of the peat found with the harpoon

gives Clark's theory a boost.

Further analysis shows that it formed

in freshwater, not saltwater,

confirming the weapon was lost on land.

In the ensuing decades, more evidence comes in,

providing more support for this theory.

Fishermen begin to pull up bones

from a variety of land animals,

hippos, bears, woolly rhinos, saber-toothed cats.

They find more stone tools,

and even pieces of a Neanderthal skull.

After decades of clues,

the mystery comes into sharper focus

when researchers manage to extract DNA

from the ancient skull.

Turns out he was a young man

who was a meat eater with a stocky build,

and he lived about 60,000 years ago.

The incredible discovery

leads researchers to name the area Doggerland,

after a nearby sandbar.

But the real breakthrough comes

when oil and gas companies lend a surprising hand.

Using underwater survey data,

they are able to create detailed 3D models of the seabed.

This wasn't just an archipelago

of islands or a land bridge.

Doggerland was vast and teeming with life,

which attracted bands of Mesolithic hunters.

At its peak, Doggerland was big.

It stretched over 70,000 square miles,

bigger than the state of Illinois.

Then around 8,000 years ago,

the Ice Age ends and temperatures start to rise.

Glaciers begin to melt and water levels rise.

And over the next 3,500 years,

Doggerland slowly disappears beneath the sea,

causing its people to have to relocate.

Today, Doggerland is one of the best preserved

prehistoric landscapes ever discovered.

Finding a whole ancient world

hidden under the sea is incredible.

Our next big discovery takes us even further back in time,

and it's on an even bigger scale.

In 2017, a man in Pombal, Portugal

is trying to expand his garden.

He starts digging and digging,

and suddenly, he hits something really hard.

Now, this is deeply unusual because the soil there

is pretty loose and sandy.

He bends down to take a closer look,

brushes across the soil with his hand,

and he sees some sharp fragments.

He takes a closer look,

and he thinks that they look very much

like pieces of fossilized bone.

The man reaches out to the University of Lisbon,

who sends a team of paleontologists to investigate.

They confirmed that these are indeed fossil fragments,

and then a deeper investigation ensues.

Pretty soon they find another fossil,

but this one's no tiny fragment.

This time, they find a complete bone.

They uncover three feet of it, four feet of it.

And there's still more in the ground.

Ultimately, when they retrieve it,

it's 10 feet long.

This is one of the largest ribbed fossils

ever recorded.

So scientists ask, what could this giant animal be?

From the shape and the size,

they are able to determine that these bones

come from a sauropod.

Sauropods lived over 100 million years ago

and are the largest land animals to ever roam the Earth.

Sauropods were herbivores.

They had a long neck, long tail,

and they grew into the largest dinosaurs ever.

With very tiny heads

because, you know, how much weight do you wanna put

at the end of a 40-foot lever?

The long necks allowed them to graze

over a wide area of vegetation without having to move.

And they had to do a lot of grazing,

because sauropods could weigh as much as 50 tons.

Experts estimate that the individual

uncovered from the backyard in Portugal

was probably close to 40 feet tall and around 80 feet long,

roughly the size of a tennis court.

It's one of the largest dinosaur specimens

ever found in Europe.

Despite millions of years passing,

the ribs are still in place and aligned

just like when the dinosaur was alive.

That's really unusual for fossils this old.

Hopefully the rest of the fossils

from this magnificent beast will be found

and it'll be stalking the floors of a museum very soon.

For one man in Turkey, a small remodel

opens the door to a whole buried world.

It's 1963 in the Cappadocia region of Central Turkey,

and a man is remodeling his home.

But he keeps having a strange predicament.

His pet chickens keep disappearing.

He starts investigating

and he traces the problem to the basement,

where he finds a small opening in the wall.

Curious and frustrated,

he grabs a sledgehammer and knocks it down.

Behind the wall, there's a cavity.

Not a pipe, not an old cellar,

but a tunnel.

He climbs through the wall and starts to walk.

One tunnel becomes two.

And then it connects to different chambers.

And eventually,

it seems to stretch off into a dark distance.

Fully weirded out, the man retreats back to his house

and informs the local authorities.

Investigators inspect the tunnels,

and what they uncover is beyond anything anyone imagined.

It's an enormous, ancient, underground city.

This sprawling maze spans over 170 square miles.

It reaches 18 stories, 280 feet below the surface,

and is carved into hardened volcanic ash called tuff.

But what's truly unbelievable

is that it was originally built around 3,000 years ago.

The city is named Derinkuyu,

after the town that sits above it.

And it wasn't just a place to hide,

it was a fully functional underground city.

There are schools, churches, a convent, apartments,

even an underground wine press.

The upper level was found to have stables

where they kept livestock

so that the odors would not penetrate

down into the lower levels where people lived.

They truly thought of and designed

everything that humans would need

to carry out life underground.

There are over 50 ventilation shafts

that ensure that fresh air is delivered to all levels.

And there's a well that reaches over 180 feet

to fill numerous water tanks.

It's an engineering marvel.

There's also a security system.

Several tunnels have enormous,

1,000-pound millstone doors

that could be used to close off the tunnels from inside.

Each door has a hole right in the center,

big enough for a spear to poke through.

But who built it and why remain a mystery.

Archeologists find a Hittite statue of a lion

and other relics during their excavation.

This leads some to believe that the Hittites built the city

as their last refuge

when their capital was under attack from the Phrygians

in the 12th Century BC.

Others believe

that this kind of incredible construction

could only have been the work of the Phrygians themselves.

But one thing that's clear is that the original builders

were not the only ones that lived here.

Eventually, Derinkuyu was inhabited

by Byzantine-era Christians

who used the city to avoid persecution,

which explains the cruciform church on the lowest level,

18 stories down.

Altogether, researchers find

more than 600 hidden entrances,

including one that extends much further

than anyone thought.

Researchers find a five-mile tunnel

that connects this subterranean world

to another underground city called Kaymakli.

This city is smaller, less elaborate than Derinkuyu.

But the design is nearly identical.

Over the ensuing years, they find over 200 more

of these underground cities spread throughout the region,

each one a sleeping giant carved in stone

that serves as a monument to survival.

Our next discovery takes us

to a very different kind of hidden world.

This time, in Rome.

It's 2006 in Rome,

and workers are drilling test holes

ahead of the construction

of a new underground parking garage.

That is, until their drill hits something unexpected.

As is the way in a city

with as rich and ancient a history as Rome,

when you're digging and you hit something strange,

you need to stop and investigate.

The workers take a closer look,

and they find pottery shards,

then pieces of jewelry.

So they ultimately call in the archeologists to take over.

They uncover more pottery, parts of a fountain,

and even the foundations of a portico.

Then they find something really unusual,

a piece of glass

filled with transparent, crystal-like stones.

The crystal stones are a major clue.

In 40 AD, the philosopher Philo

describes seeing this kind of glass with these crystals

on a visit he made to the Roman emperor Caligula.

The archeologists realize

they found Caligula's long lost, infamous pleasure garden.

Caligula was the third emperor of Rome,

and many consider him to be the most eccentric.

Some accounts say he believed he was a god.

Others say he was just insane.

But either way, his behavior was bizarre.

He once made talking about goats in his presence

a capital offense.

He would appear in public dressed like Greco-Roman gods

like Venus and Apollo.

He once declared war with the sea,

and even appointed his horse consul to the Senate of Rome.

But Caligula took excess

to a whole new level in his pleasure garden.

Caligula surrounded himself in luxury.

So when he wasn't feeding Romans to the lions,

or sleeping with his political rivals' wives

or even his own sisters,

he enjoyed spending time in his pleasure garden.

Excavations revealed frescoes

inlaid with rubies and precious stones,

marble staircases, and also pieces of jewelry.

They also find animal bones, but not pets like cats or dogs.

The bones they find are from lions, from bears,

from ostriches, from peacocks,

just rare and exotic animals

brought in to impress his guests and to make himself out to be

this larger-than-life, hedonistic, godlike figure.

Ultimately,

Caligula's reign of indulgence didn't last.

After just four years in power,

Caligula was assassinated by his own bodyguards.

His body was cremated in the garden he loved.

By the fourth century, the garden is abandoned

and fades from memory

until it's rediscovered in 2015.

When archeologists finally finish the excavation,

over 100,000 artifacts are uncovered.

Today, the site has been transformed into a museum,

and it contains many of those very same relics

and preserved architecture.

Compared to the legend of his life,

the ruins of his pleasure garden are surprisingly tasteful.

But the jewels, the baths,

the exotic animals do point to one thing:

Caligula threw one hell of a party.

And 2,000 years later, we're still cleaning up after it.

In 1992, a man sets out to solve a local legend,

but instead uncovers a long lost engineering wonder.

It's 1992 in the Zhejiang Province of China,

and farmer Wu Anai is a man on a mission.

He's just bought a water pump.

And with the help of his neighbors,

he's trying to drain a pond in his hometown of Longyou.

It sounds crazy.

But for generations, locals have passed down tales

that the ponds are bottomless,

and Anai is determined to get to the bottom of this legend,

so he turns on the pumps and watches.

As the water recedes,

it reveals more than just mud and stone.

When Anai peeks into the hole, he can't believe his eyes.

Beneath the surface of this pond

is actually a massive, man-made cave.

Its walls are intricately carved,

its ceilings are held up by pillars,

and every inch is decorated

with these chiseled parallel lines.

Anai and his neighbors cannot believe what they found,

so they go and they drain more ponds in the region.

Sure enough, they find four more caves,

each as elaborately carved and decorated as the first one.

These things are huge, ranging from 25 to 60 feet deep

and 50 to 100 feet wide.

Just as impressive is the engineering.

The sloped walls help distribute weight,

preventing collapse from the ground above.

Every cavern faces south,

which allows the caves to be filled with natural light.

Over the next few years,

researchers find 19 more hand-carved caves.

We have over 300,000 square feet of engineered space,

but no signs of the builders,

the techniques, or of their intentions.

This lack of cultural or material evidence

is unprecedented.

Archeologists date their construction

to between 206 BC and 23 AD.

This makes them the biggest

underground construction project of that era.

This is a project on par

with other monumental architectural wonders

like the Great Pyramid of Giza.

As mysterious as the pyramids are,

these caves are even more so.

Some researchers have suggested

that the caves might have been used to store grain.

Others have thought that they might have been a mine

for natural resources.

And then there are those

who think that these hidden structures are so secretive

that they must've been used for religious

or other cultural ceremonies for the elite.

With little to go on,

the mysterious caverns become known as the Longyou Caves,

named after the town where they were found.

In China, they're considered

the ninth wonder of the ancient world.

But for all their size and sophistication,

they raise more questions than answers.

The fact that we still don't know who built the caves or why

makes them one of the most fascinating mysteries

of the ancient world.

Anai's curiosity uncovered an ancient mystery.

A find 20 years later in Serbia

reveals something even stranger.

It's July 2023

in the small mining town of Kostolac in Serbia.

Miners are busy excavating in a quarry

when about 25 feet deep,

their mechanical digger hits something really hard.

It sounds like wood,

so they figure that it's a buried tree trunk.

But they decide to play it safe and take a closer look.

When the workers brush some of the dirt away,

they confirm it definitely is wood.

However, this is definitely no tree.

It's got sharp, crisp lines.

It's been carved by man and it looks really old.

Archeologists are called in to examine the site.

And as they dig, the find gets bigger and bigger

from one point to another, to dozens.

They've uncovered a massive wooden structure.

It's the remains of an enormous riverboat.

Now that it's exposed,

archeologists rush to fully dig out the boat

before it falls apart.

It takes them two days to fully uncover the boat

and it's huge, it's 65 feet long, it's 11 feet wide.

Researchers believe it was a cargo vessel

crewed by up to 30 men.

But curiously, there's no cargo, there's no personal items,

there's no human remains.

Even stranger, it's underground

and miles away from the nearest waterway.

The Danube River is more than two miles away,

but it turns out that it has shifted over the centuries.

Researchers believe that at one point

it flowed directly over this spot.

The ship likely sank here,

and then the river changed course

and then the ship was left

to be buried by the shifting sands.

The whole area seems to have changed centuries ago

because just a mile away,

there's an even larger archeological excavation.

The ancient port of Viminacium.

Viminacium was a major ancient Roman trading hub

and military port that boasted a population

of about 45,000 people.

Its ruins included temples, theaters, palaces,

even a hippodrome.

Beginning in the fourth century,

Viminacium was attacked by invading forces,

including Attila the Hun

in his campaign against the Roman Empire.

By the time the Roman Empire began to collapse in 476,

Viminacium was abandoned.

Experts conclude the buried ship

was likely servicing the port of Viminacium

around 1,700 years ago.

But questions still remain about its final voyage.

The ship has no signs of battle scars,

no signs of cargo, no signs of crew,

which suggests it may have been sunk intentionally,

perhaps better to lose it

than for it to fall into enemy hands.

After nearly two millennia underground,

this river barge is still a mystery,

but at least it's finally returning to port.

Road construction usually slows you down.

But in 2024, it stopped everything

when crews in Mexico hit something incredible.

In June of 2024, just outside of Mexico City,

construction workers are expanding Highway 105.

As the workers labor under the blazing summer sun

trying to dig out a hillside to create space for a new lane,

they hit an unexpected obstacle.

It's a flat stone, which is pretty strange,

but stranger still is that it is attached

to another flat stone, and another flat stone,

and they're all linked together by mortar.

All these stones form a steeply pitched wall

buried underneath the mountain.

They realize this is clearly part of a structure.

They halt all work and they call in the archeologists.

As they dig up this angled wall,

it appears to stretch in two directions.

One, up the side of the mountain,

and two, down towards the road.

Soon, they begin to make out a shape.

They find stepped corners on the outer edge of the wall.

And behind that, another wall continues

at a 90-degree angle.

This crew thought they were working to widen the highway.

But what they've really done

is discovered an ancient pyramid.

And not just any pyramid.

The base stretches out to around 1,000 feet,

about 25% bigger than the Great Pyramid of Giza.

Archeologists realize the pyramid dates back

to a mysterious and largely unknown ancient civilization

known as the Metzca.

The Metzca were a multi-ethnic group

that lived within the area

from around the year 950 to 1350.

Little is known about this culture

because almost nothing has been found

from the time of their reign, until now.

Unfortunately,

experts can't fully excavate the pyramid.

So they use drones and imaging technology

to scan the entire site from the air.

When they analyze the data, they're shocked.

There is an entire ceremonial complex

with the pyramid as its centerpiece.

This discovery suggests that this site

was of great significance to the Metzca,

a combination religious site and cultural hub.

And just when we're hot on the heels of learning

and uncovering this treasure trove of the ancient world,

all work comes to a stop.

Funding dries up,

and archeologists are forced to abandon the site.

Then, they actually have to rebury it

to protect the site from the elements and from any looters.

There's obviously more to uncover here,

more stories about the history

of this otherwise forgotten civilization.

But until more funding materializes, this giant pyramid

and the ancient civilization that constructed it

remains, once again, buried underground.

Across the sea in England,

another surprising relic is buried even deeper.

Not a pyramid, but a far more personal piece of the past.

The year is 1972, and in the city of York, England,

construction has just begun

on a new branch of Lloyds Bank.

They fire up the excavator

and start to haul away layers of peat.

And that's when the workers noticed that

mixed in with the soil are some strange-looking objects.

There's pieces of timber, there's textiles,

and there's straps of leather.

Archeologists are called in

and as they are sifting through these artifacts,

they find an object they can't quite identify.

It's rough and cylindrical in shape.

It's about eight inches long, two inches wide,

and it weighs about half a pound.

Archeologists take a closer look

at the mystery object under a microscope.

They see evidence of plant pollen, cereal bran,

and other organic material.

And before long, it becomes pretty evident

what they're looking at.

What they have found is an enormous human coprolite.

It's another way of saying

a gigantic piece of fossilized poop.

In fact, it's the largest intact piece

of fossilized human feces ever discovered.

What's unusual about it,

apart from its gargantuous size,

is that typically, human feces breaks down pretty quickly,

way before it has a chance to fossilize.

But in this case, because it fell in peat,

which is a low-oxygen environment, it didn't rot.

Testing puts it in the 9th century AD,

right in the middle of the Viking occupation of York.

In 866 AD, the Viking Great Heathen Army

conquered the city.

York became the Viking capital in England until 954 AD.

And based on the diet,

this coprolite was left behind by a Viking.

Today, the relic is on display

at the Jorvic Viking Centre in York.

It may not be the most important

Viking artifact ever found,

but it is a strong contender for number two.

The ocean is full of big creatures

and even bigger secrets,

but none like the one a group of fishermen find in Norway.

It's April 26th, 2019,

just off the coastal village of Tufjord in Norway.

You have a group of fishermen that are on their boat

and before long, they feel something colliding

with the side of their ship.

One of the men on board looks down in the water

and he sees a large beluga whale

rubbing itself against the side of the boat.

Even though this animal is large,

14 feet long, maybe 2,700 pounds,

it seems friendly, tame even.

Hey, hey.

But it seems to be tangled in something.

He puts on a survival suit

and jumps into the water to help free it.

But as he gets closer,

he realizes that the whale is in a harness.

So he unbuckles it and sets the beluga whale free.

Back on the boat, he sees something strange.

There's a camera mount on the harness,

but the camera itself is missing.

They also notice a stamp on the harness

that says "Equipment St. Petersburg".

So it looks like this whale came from Russia.

Nearly overnight,

the beluga becomes a media sensation in Norway.

But something seems off about this friendly giant.

This whale doesn't swim back north

towards his more natural habitat.

He instead stays in the harbor,

socializing with fishermen and tourists.

Hi, hi.

I mean, the whale, he seems too well trained

to be a wild whale.

That's when Norway's domestic intelligence agency

puts two and two together,

and comes up with a shocking theory.

The strange behavior, the harness,

the familiarity with humans.

This whale was clearly trained to perform specific tasks,

which leads investigators to hypothesize

that this whale is an intelligence-gathering spy.

For years, rumors had spread

around intelligence circles

that the Russian Navy was actively trying

to get their hands on aquatic animals

to train them as Russian spies.

Now, of course, Moscow denies

that any such program ever existed.

Although there was that one time that they placed a newspaper ad

seeking to buy five bottlenose dolphins for $24,000.

As unlikely as it seems,

the spy whale theory picks up momentum,

leading investigators straight to a possible source.

Intelligence officers comb over satellite imagery

and, indeed, they find a nearby Russian naval base.

The base has large sea pens

that would be perfect for housing beluga whales.

They conclude that this beluga either escaped from its pen

or that it might have actually become lost

during a training session in open waters.

In honor of his Russian roots,

the whale is given the name Hvaldimir,

combining hval, which means whale in Norwegian,

with Vladimir, as in Putin.

Sadly, Hvaldimir's story does not have a happy ending.

In 2024, his body is discovered floating

in Risavika Bay in Norway.

Of course, given his reported spy background,

rumors began to fly that he's been taken out

by the Russians.

But the Norwegian Veterinary Institute does an autopsy

and determines that Hvaldimir died

from a bacterial infection.

To this day, Russia has neither confirmed

nor denied Hvaldimir's origins.

But one thing is certain,

whether he was a runaway spy or just a very confused beluga,

this giant whale left behind a legacy

that was larger than life.

A colossal city buried in the jungle,

a massive mammal working as a secret agent,

and a metropolis unearthed 200 feet below the surface.

Sometimes gigantic discoveries

lead to even bigger revelations.

I'm Danny Trejo.

Thanks for watching Mysteries Unearthed.