All language subtitles for Hidden.Beneath.the.Cities.S01E09.Subterranean.Seoul.and.Railway.Revealed.1080p.DSNP.WEB-DL.DDP5.1.H.264-KHN_track3_[eng]

Below the bustling
streets of Seoul, South Korea,

an incredible discovery
is made.

Beneath CitiStar Mall
lies a vast chamber

just above the tracks
of subway Line 2.

How does a space
like this get constructed

in the middle of the city

then stay hidden from
public view for so long?

What function was
it meant to serve?

Excavations beneath
a Polish ice cream shop

reveal a medieval gravesite.

The first discovery
was a limestone slab

carved with the image of a man
in full chainmail armor.

So who was he?

And what can his burial
reveal about the forces

that shaped the city
at its beginnings?

A remarkable
discovery is made

under the rubble of
a demolished church in England.

Three portrait
busts made of stone.

This site was like
an archaeological nesting doll,

each layer presenting
a new mystery.

Who put
all these items here

and what was this place?

Below the busy
streets of the world's cities

exists a hidden
realm of wonder.

Sprawling ancient complexes,

mysterious tombs,

top-secret military bases,

strange structures,

and lost artifacts,

buried beneath our feet
and long forgotten...

until now.

Underground marvels are exposed
to reveal what lies...

Hidden Beneath the Cities.

Less than 40 miles
from the Yellow Sea,

the city of Seoul is located
in South Korea,

which makes up the southern
part of the Korean Peninsula.

The Korean Peninsula stretches

over 600 miles
from north to south,

bordered by China and Russia,

with Japan just across
a narrow strait.

A position that has made Korea
both a cultural bridge

and a focal point
for rival powers.

Today, South Korea covers
over 38,000 square miles

with more than 52 million people

packed into one of the world's
most densely populated nations.

In 1910,
Japan seized control of Korea,

erasing its sovereignty
for the next 35 years.

After Japan's surrender
to Allied forces in 1945,

Korea was divided
into Soviet and American

zones of occupation.

Two rival regimes
emerged in 1948.

North Korea with its capital
in Pyongyang,

and South Korea with
its capital in Seoul.

Two years later,
the Korean War erupted,

leaving at least two and a half
million people dead.

The armistice of 1953
ended the fighting,

but didn't formally end the war.

And the peninsula remains
divided to this day.

Devastated by
war, Seoul was rapidly rebuilt

as waves of refugees
and workers poured in.

In the decades that followed,

South Korea's rise as one
of Asia's "Four Tigers"

turned the capital
into a metropolis

of roughly 10 million.

Today, it anchors the nation's
political power,

economic strength,
and cultural life.

In September of 2023,
a hidden underground space

beneath Seoul Plaza
opens to the public

for the first time in 40 years.

Beneath CitiStar Mall,

Seoul's first underground
shopping center,

lies a vast chamber.

It's about 43 feet underground,

just above the tracks
of subway Line 2,

stretching between two stations,
City Hall and Euljiro 1-ga.

The tunnel measures
nearly 1,100 feet long

and just over 30 feet wide.

Altogether, it spans
over 34,000 square feet.

Above this chamber,
there's a drainage system,

and for decades water has
dripped from the ceiling.

Over time, those steady drips
have built a stalagmite,

a mineral column that
rises from the floor,

gradually building upward

as each drop deposits a thin
layer of calcium carbonate.

Despite its massive scale,

we don't know exactly why
this chamber was built.

So, how does a space like this
get constructed

in the middle of the city

then stay hidden from
public view for so long?

What function was
it meant to serve?

In the 1960s and '70s,

Seoul became the engine of
South Korea's transformation

as mayors pursued
urban planning

with the discipline
of a wartime campaign.

But this was also a period
of escalating tension

with North Korea, when even
everyday spaces could be shaped

by the logic of defense.

After incidents
like the 1976 murders

of two US officers

and the discovery of secret
infiltration tunnels

from the north, Seoul began
building underground shelters

and even designing
some public spaces

with emergency use in mind.

So could the chamber
beneath Seoul Plaza

have been part of that strategy?

Maybe it was a place
to protect its citizens

or government officials
in the event of an attack.

Seoul's explosive
population growth

drove rapid urbanization
and industrial expansion.

Ex-military mayors pushed
sweeping redevelopment.

They expanded
Seoul's boundaries,

built expressways and
large-scale apartment complexes,

and created new towns
in the city's south,

considered safer from attack.

In this era, urban planning
wasn't just about

establishing a global presence,

it was intertwined
with national security.

Tensions between
north and south

were already high when a new
threat emerged underground,

roughly 30 miles north
of Seoul Plaza.

In 1978, authorities
uncovered the so-called

"Third Tunnel of Aggression,"
the third such passage

discovered beneath the
Demilitarized Zone since 1974.

It extended over 1,400 feet
into South Korea

and was believed to stretch
nearly 4,000 feet

back into North Korea.

Carved nearly
240 feet below ground,

and measuring about
6.5 feet high and wide,

it was large enough
for military vehicles,

field guns, even tanks.

Experts estimated as many
as 30,000 troops

could have passed
through every hour.

Adding to the tension
was the fact that the tunnel

opened toward
the Munsan Corridor.

That's the same route used
by North Korean forces

to reach Seoul in 1950.

Back then the US called it
an "act of aggression."

But to South Korea, it was just
evidence that the North

had never really
abandoned its policy

of reunification by war.

The discovery also
underscored a sobering reality:

the capital, which lies
roughly 25 miles

from the Demilitarized Zone,

was still within
easy reach of attack.

In that climate, it made sense

for Seoul to look underground
for its own defenses.

Perhaps the tunnel
under Seoul Plaza

was part of that response.

In 2005, construction
workers in Yeouido,

just three and a half miles
from Seoul Plaza,

were building a new bus station

when they uncovered what
looked like a hollow void.

Further investigation revealed

it was actually
a deliberately built bunker,

reportedly with
no official records

to explain its existence.

The bunker's layout
consists of two zones:

a living quarter
of over 700 square feet,

complete with a sofa, shower,
and bathroom,

and a sprawling machine room
covering over 6,000 square feet.

These features suggest
that it was intended

for a small number of VIPs.

Its construction appears
to date to a period

of renewed Cold War tension.

Aerial photos from 1977 reveal
what seemed to be its doors,

while none were present
in images from 1976.

It sits directly
beneath the raised platform

from which President
Park Chung-hee would watch

military parades
staged to project

South Korea's strength
to the North.

And so many believe
the bunker was built

for him and his bodyguards
as a secure refuge

in the event of an attack.

The location and
the general vibe of the bunker

at Yeouido point very clearly
to a government function.

But the Seoul Plaza chamber
is different.

It's way bigger,
it's way less defined,

and it's just harder to explain.

There's no evidence
to suggest it was built

to protect government officials
or even civilians,

so maybe we've been barking up
the wrong tree altogether.

But if so,
what was it built for?

Not all
interpretations

center on defense.

Some see the chamber as
a reflection of South Korea's

own political landscape.

The Korean
Central Intelligence Agency

was once arguably the most
powerful institution

in South Korea.

Created in 1961
with American support,

one US official described it

as "a combination of the Gestapo
and the Soviet KGB,"

reflecting the scale of
its authority and methods.

If the agency could
dominate politics,

intimidate communities abroad,
and operate with such secrecy,

could a hidden chamber
in central Seoul

have served as part
of its operations?

By the early 1970s,
the KCIA's reach was absolute.

It was accused of extorting
money from businessmen,

abducting dissidents,
torturing students

on fabricated espionage charges,

and later even engineering
the 1987 bombing

of a Korean Air flight
that killed 115 people.

In that climate, the idea that
underground facilities

might have been built
for intelligence use

really isn't far-fetched.

Less than a mile
away, at the base of Namsan,

a scenic tree-covered peak
in the heart of Seoul,

the KCIA's operations in
their own facility's basement

show how subterranean
spaces in Seoul

have served
far darker purposes.

The KCIA headquarters
on Namsan opened in 1973,

the same year a Seoul National
University law professor died

while in the agency's custody.

Officials claimed
he had confessed to being

a North Korean spy
and jumped from a window.

But in the year 2000,

South Korea passed
a law to honor,

and in some cases, compensate
the people who took part

in the country's
democracy movement,

creating a commission
to review individual claims.

And that commission
later concluded

that the allegation
was fabricated

and that he had most likely been
thrown from the building

or even tortured to death
beforehand.

Possibly the first victim
inside the new headquarters.

Namsan soon
became synonymous

with state repression.

In South Korea's post-war
authoritarian years,

"going to Namsan" meant
ending up in KCIA custody,

often for involvement
in pro-democracy activities

where torture was common.

The KCIA's record
leaves little doubt

about its capacity
for secrecy and abuse.

Its power radiated from
the Namsan headquarters,

while abroad, its agents
operated through embassies,

consulates,
and front organizations.

But nothing in the public record
suggests that it used

the vast hidden chamber beneath
Seoul Plaza for its operations,

which opens up
other possibilities

about its true purpose.

The official explanation

is the most straightforward
and the least sensational.

When Seoul began
building its subway

in the early 1970s, construction
methods were very different

from what we see today.

Could the chamber
beneath Seoul Plaza

simply be a byproduct
of that process?

The evidence
does line up.

The chamber lies
right between Euljiro 1-ga

and City Hall stations.

And during the construction
of Line 2,

when it's believed this
underground space was created,

crews were digging down
from the surface

instead of boring a tunnel
in from the side,

which is how these things
are done today.

So officials believe that
when Euljiro 1-ga station

opened in 1983, this leftover
space got sealed off

and then just remained hidden
for more than four decades.

Over 6,700 miles
across the Pacific,

in Cincinnati, Ohio,
a similar underground void

tells its own story

about a subway line
that never came to be.

In the early
20th century,

Cincinnati set out to build
a 16-mile rapid transit loop

to serve its booming population.

By 1923, two miles of the subway
tunnels were completed

to a spot just north
of the Western Hills Viaduct

with a short tunnel running
beneath Hopple Street

as part of the city's grand plan
to modernize its transit system.

But costs spiraled
after World War I.

Funds dried up,
and planning was scaled back.

By 1929, the project
was abandoned.

Tracks were never laid,

and crucial links to the system
never finished.

The tunnels were sealed off
and ultimately sidelined

by the Mill Creek Expressway,
today's I-75.

Over the years, the abandoned
subway was reimagined

for everything
from fallout shelters

to underground wineries.

But in the end, it remained
what it had always been,

a relic of unfinished planning.

The official
explanation in Seoul

points to leftover
subway construction,

and it makes sense.

With more than 65% of the land
covered by mountains,

tunneling has become unavoidable
for railroads, freeways,

subways, and
the utility networks

buried beneath
South Korea's cities.

The chamber under Seoul Plaza
may simply be one of them;

an ordinary remnant of
extraordinary infrastructure.

Hidden for decades,

the chamber beneath Seoul Plaza
is now in plain view--

a reminder that even the most
familiar urban landscapes

can contain histories we're
only just beginning to uncover.

175 miles northwest of Warsaw,

where the Vistula River
meets the Baltic Sea,

Gdansk has endured
for centuries as a city

defined by commerce,
conquest, and resilience.

In 1260, Gdansk secured
municipal autonomy,

granting merchants the freedom
to expand their trade.

Its position at the mouth
of the Vistula

made it Poland's main outlet
for grain and timber,

tying the city directly into
northern Europe's trade routes.

In 1308, the Teutonic
Knights seized Gdansk.

Invited east decades earlier,

the German Catholic military
order had already carved out

a state in Prussia with
papal and imperial backing.

Their conquest of the city

shifted the balance of power
across the Baltic.

From Gdansk, they ruled
more than a century

until King Casimir IV reclaimed
it in 1466 after a 13-year war.

Casimir restored
broad civic privileges,

fueling prosperity.

By the 18th century,

Gdansk could become
the Baltic's leading port,

home to 77,000 people

and exporting over 200,000 tons
of grain each year.

But even in modern times,

the fortunes of Gdansk
rose and fell with conflict.

It was remade as the Free City
of Danzig after World War I,

absorbed into Nazi Germany
in 1939,

reduced to ruins in 1945,

and later rebuilt.

In July of 2025,

excavations beneath the site
of a former ice cream shop

in the center of Gdansk uncover
traces of a medieval past

long hidden beneath the city.

The first discovery
was a limestone slab,

thought to be a tombstone
about 60 inches long,

carved with the image of a man
in full chainmail armor.

He's gripping a sword
in his right hand,

a shield in his left hand,

with boots and leggings
encasing his legs.

Monuments of this kind
are exceptionally rare

from medieval Poland,

where tombstones almost never
depicted the deceased

in such vivid detail.

The slab was lifted,

and after two more days
of excavation,

they found a coffin below.

Inside lay the skeleton
of a man,

surrounded by 23 field stones

carefully arranged
in a rectangle.

Preliminary analysis showed

that he was about
40 years old at death

and stood between 5'6" and 5'9",

close to the average stature
for men in medieval Gdansk.

The grave lies within
a larger excavation zone,

spanning nearly
11,000 square feet,

which has uncovered traces
of the city's earliest history--

wooden cottages,
a 12th century timber street,

and Gdansk's first church,

built around 1140
in the form of a Greek cross.

The slab dates to the
late 13th or early 14th century,

and even after
centuries underground,

the outlines of the armor,
sword, and shield

remain strikingly
well preserved--

a monument to a man of clear
status whose identity is lost.

So, who was he?

Why was he buried here?

And what can his burial
reveal about the forces

that shaped the city
at its beginnings?

In a city where
wealth once flowed

through merchant hands, the
tomb may reflect the ambitions

of a man who blurred the line
between commerce and chivalry.

After the mid-15th century,

Gdansk was dominated by
a merchant patriciate--

families who controlled trade,
held civic office,

and displayed symbols
of elite status.

They worked to secure shipping
routes, guard against pirates,

and manage commerce,

competing directly with
English and Dutch rivals.

Could this burial
belong to one of them?

The slab itself
is a major clue.

It was carved from
Gotland limestone,

an expensive material that was
imported from the Swedish island

at the heart of Baltic Exchange.

That kind of stone
would have reached Gdansk

through trade routes, suggesting
that the man in this grave

had direct access
to the networks

of the ruling merchant class.

Over 800 miles northwest

on the Scottish island of Unst,
another site shows

how merchants marked their
presence far from home.

In the chapel ruins
at Lunda Wick,

a weathered imported slab
still honors a German merchant

who traded there for
more than half a century.

Its inscription lists his name,
city, and profession;

a grave that doubles
as a statement

of mercantile identity.

In Gdansk,
the pattern is different.

The knight's effigy bears
no merchant's seal,

no inscription,
no mark of trade;

only the imagery of sword,
shield, and armor.

Nearly 115 miles
south of Gdansk,

in the Kuyavia region
of north-central Poland,

archaeologists uncovered a cemetery

of several dozen chamber graves

dating to the late 10th
and early 11th centuries.

Four rows of graves
contained the remains of 14 men,

21 women, and 14 children.

Each lay within a wooden box
reinforced by iron fittings

and lined with fabric,

with some graves marked by
larger rectangular enclosures

that may have been fences,
or houses of the dead.

Alongside them,
richly furnished cenotaphs

added further evidence
of high status.

These burials were
filled with remarkable items:

weapons, jewelry, coins,
and ornaments of high quality.

Women were laid to rest with
necklaces of glass beads,

gold foil beads,
precious stones, and silver.

Two silver amulet containers,
one engraved with a bird,

stand out as truly
spectacular finds.

The discovery of silk fragments,

likely brought from
as far away as China,

shows just how far

the community's
trade connections reached.

Weapons in the men's graves--

Viking swords, a pickaxe,

and single-edged
Langseax blades,

which were long, straight-edged
knives used in battle

and as markers of status--

reveal a warrior elite whose
funeral rites and equipment

marked them as
high-status settlers.

The most striking case
is a young man

buried with a silver-inlaid
ceremonial sword

bearing a Rurikid tamga,

a symbol of the noble lineage
that ruled the Land of the Rus',

which is evidence
of far-reaching ties.

At this site, we see
evidence of trade connections,

where wealth was displayed
through weapons,

ornaments, and foreign imports.

But in Gdansk, there are no
weapons, no jewelry, no silks,

only the carved image
of a knight.

That absence makes it
less likely

he was a wealthy merchant, and
instead, opens the possibility

that his identity was
defined in other ways.

Long before
merchants and crusaders

left their mark on Gdansk,

power rested in the hands
of a native dynasty.

The Sobieslawice
Dynasty emerged in Gdansk

in the 12th and 13th century,
ruling for nearly a century.

Its founder began as a governor,

but from 1227, his heirs
styled themselves as dukes,

princes in their own right.

Could this have been a duke
of their dynasty?

Excavations around
the slab uncovered layers

of early settlement--
timber cottages,

a street built from
18 successive layers of wood,

and nearly 300 burials.

Only eight of those graves
had stone markers,

and the knight's was
by far the most elaborate.

That distinction suggests
elite rank in a modest cemetery,

consistent with
a dynastic identity.

Most members of the
Sobieslawice Dynasty were buried

in a monastery
they found at Oliwa,

but their original graves were
destroyed several times

by fire and war.

That loss makes the Gdansk
effigy all the more significant.

If it belonged
to one of their princes,

it could be the earliest
authentic ducal monument

still tied to the dynasty.

In 2018,
a burial chest was discovered

hidden in a storeroom,

walled up inside
St. Stephen's Church

at the Czech city of Olomouc's
Hradisko Monastery,

around 330 miles
southwest of Gdansk.

Decorated
with elaborate artwork,

it held the skeletal remains
of seven members

of the Premyslid Dynasty.

These were princes
and princesses

who ruled Bohemia and Moravia
from the 9th to 14th centuries.

Their identities were confirmed

only after DNA
and radiocarbon testing.

The Sobieslawice
princes of Gdansk

belong to the same
medieval world,

and both groups' original tombs
have been destroyed over time

by disaster or conflict.

But in Gdansk,
the difficulty is twofold.

The effigy bears no name
or inscription,

and it lies outside
the dynasty's

known necropolis of Oliwa.

Its stark military imagery may
instead hint at another power

that would soon
dominate the city.

The tombstone
may reflect status,

but its stark simplicity
could connect

to Gdansk's most
infamous occupiers.

After a campaign
of expansion,

the Teutonic Order carved out
a militarized state in Prussia.

In 1308, the Teutonic Knights
seized Gdansk

in a brutal massacre, placing
the city under their rule.

Could the man in this grave have
once belonged to their ranks?

The conquest of 1308
gave the order direct control

over eastern Pomerania.

From Gdansk, they expanded
deeper into Prussia,

building castles, churches,
and monasteries.

A high-status burial from
this moment of transition

would fit within
the order's sudden,

violent presence in the city.

In the early
14th century,

Teutonic Knights in Gdansk
swore vows

of poverty, chastity,
and obedience.

A lone stone tool marked
with martial symbolism

but devoid of goods

is exactly what we might expect
of their burials.

The order also drew
guest crusaders

from across Europe.

Nobles would join seasonal
crusading campaigns

known as reysen

against Poland and Lithuania.

Many would have died on campaign
far from their homelands.

With so many foreign knights
passing through Gdansk,

it is possible that
one was buried here.

Less than 30 miles
southeast of Gdansk,

in Malbork, the Teutonic Order
built its greatest fortress,

Malbork Castle.

Beneath it,
the Chapel of St. Anne

shows how they buried
their most powerful men.

The Chapel of St. Anne
was likely built

in the 14th century
as the burial place

for the Grand Masters
of the Teutonic Order.

Dietrich von Altenburg was
the first Grand Master

to be interred beneath
its floor in 1341.

Ten of his successors
were buried here, too,

making it the order's
symbolic necropolis.

Ordinary knight
burials were very different.

The Teutonic rule banned
personal seals, coats of arms,

and ostentatious monuments.

Even clothing and equipment
were tightly regulated.

Against that discipline,
a solitary effigy

with only military imagery fits:

not a grand master
celebrated in ritual,

but perhaps a single knight
remembered in the simplest way.

Researchers are
scanning the effigy in 3D

and testing the bones through
chemical and genetic analysis,

aiming to uncover who this
knight was and how he lived.

They even plan a facial
reconstruction from the skull,

so the so-called Gdansk Lancelot

may soon be seen as he
once appeared in life.

Beneath the streets
of Gdansk,

the carved tomb of the night

carries the weight
of a city's beginnings;

a trace of power preserved,
but never fully explained.

In southern England,
just outside Greater London,

is the ceremonial county
of Buckinghamshire.

This part of Britain

has seen centuries
of human history.

People have found evidence
of Neolithic

and Bronze Age occupation
across Buckinghamshire.

The hillfort at Ivinghoe Beacon
was likely occupied

long before the Romans
ever invaded.

But after that invasion,

Rome began construction
on Watling Road,

which would ultimately connect
this whole region

to what would later
become London.

Buckinghamshire's
more recent history

highlights British
determination and perseverance.

In World War II, it was here
that the Allied codebreakers

managed to crack
the German Enigma Codes,

which helped bring the war
to a close much sooner.

But it hasn't always
been easy for Buckinghamshire

to hang on to its
physical history.

One building lost to
the past is St. Mary's Church

in the village of
Stoke Mandeville.

Demolished in 1966,

St. Mary's rubble sits
undisturbed until 2021,

when the city must make room

for a new national
high-speed railway.

But prior to its removal,

researchers conducting
a routine archaeological survey

of the site discover much more
than they bargained for.

Beneath the foundation
of the church,

another structure emerged
from the earth and rock.

There were the foundations of a
smaller, square-shaped building,

possibly a tower of some kind.

When the surrounding ditch
was excavated,

some incredible artifacts
were unearthed:

three portrait busts
made of stone.

This site was like
an archaeological nesting doll,

each layer presenting
a new mystery.

The busts depict
an adult male, an adult female,

and an additional head

that seems to be that
of a young child.

But what's weird is that the
adult busts appear to have been

decapitated before
they were buried.

There are clean breaks
at the necks.

And there's something else.

The remnants of a hexagonal jug
made of glass.

Who put all these items here
and what was this place?

The St. Mary's site
is a multi-layered discovery,

with each stratum offering its
own piece of British history.

We know that St. Mary's
was built in 1080 CE,

shortly after
the Norman conquest.

But the style of the busts
are indicative

of early Roman sculpture,

dating them sometime between
the 1st and 5th century.

During this time,
the region was dotted

with large Roman
farming estates.

Agriculture was a major driver
of the economy.

The nearby Roman town
of Magiovinium may have been

the location of a garrison
and a Roman fort.

Magiovinium also shows evidence
of multiple cemeteries.

People likely came here
to bury their dead.

But the shards
of the hexagonal glass jug

complicate
the historical picture.

Jugs like this were often used
as funerary vessels

for flasks of holy oil.

So what's it doing here?

Why was this vessel
buried in a ditch

alongside these
Roman sculptures?

Approximately 50
miles from the St. Mary's site

in Kent, near the town
of Eynsford,

is the Lullingstone Villa
residence,

where similar high-quality
portrait sculptures

were discovered in 1949
by G.W. Meates and others.

The Lullingstone
residents had two busts

made of marble, possibly
depicting a man and his father,

and they were found

in the building's so-called
"cult room."

So, maybe the sculptures
under St. Mary's

had a similar spiritual meaning.

The stone busts were
likely commissioned

by someone of great wealth
and influence,

which further
supports the notion

that many Roman inhabitants
from this area

were from an affluent class.

These are families that
could afford a statue

carved by skilled artisans, like
the ones found under St. Mary's.

But why would
a private residence be built

on top of this natural
mound of dirt?

So far, nothing has tied these
busts or the glass vessel

directly to a neighboring villa.

The remnants of plaster
and the roof tiles suggest

that the busts and the glass

were likely buried
during a demolition.

But a demolition of what?

The building's
location may be the key

to understanding its purpose.

Natural mounds were
the go-to locations

for ancient peoples when it came
to choosing a burial site

or ceremonial center.

The circular ditch surrounding
the site is also a common trait

of an Iron Age temenos--

an enclosure that was designed
to separate the outside world

from a sacred location.

It's not hard to imagine
this site being repurposed

under Roman authority
as a temple for pagan rituals.

The busts in this
context could be deities,

or they could be
family portraits

of the temple's wealthy patrons.

As Christianity spread, the
temple may have been destroyed

along with the statues
and the glass vessel.

That could explain
the seemingly ritualistic

severing of the stone heads

that may have been a way to
neutralize a symbol of power.

In 1979,
about 65 miles away

from the dig at Saint Mary's,

in the village of Uley
in Gloucester,

a cult statue
from the second century

was pulled from
the ruins of a temple

built to honor
the Roman god Mercury.

The limestone bust,
which was a portrait of Mercury,

had its nose and lips
damaged in antiquity,

but the head itself was found
deliberately buried,

which could have happened

once the temple had been
shuttered or demolished.

This ritual burial of artifacts

is called
a structured deposition.

It was common for
Christian churches to be built

on top of former temples, a
signal to all that a new faith

had taken root in the community
and supplanted the old one.

In the case
of the St. Mary's site,

the Norman church was
built directly on top

of the Roman rubble with
no intervening soil in between.

Demolition of the Roman
structure appears to have been

followed almost immediately by
the construction of the church.

The surrounding ditch
does strongly suggest

this was a sacred site
for the Romans.

But the realistic style
of portraiture that we see

in these three busts
is more characteristic

of a commemorative statue
than a spiritual idol.

So yes, this was likely
a sacred space, but for what?

There is
another discovery

within the Roman rubble
that suggests

this mysterious building
had a special purpose.

Within all
the dust and debris,

the excavation unearthed
a bunch of Roman cremation urns.

Those items suggest
that the Roman church

was built on top
of a Roman mausoleum.

Again, the severing
of the heads on these busts

is very symbolic.

Within the context
of the mausoleum,

these decapitations could tell
a story of a family undone

by the fall of Roman Britain.

While there's no evidence

of any formal inhumations
present at the site,

the urn suggests that cremation

was the primary
funerary ritual here.

And the family depicted
in the stone portraits

were likely the occupants
of the tomb.

But there are
still questions:

Who were this man,
woman, and child?

If they represent a family,
we can infer a lot

about their wealth
and social status,

but we still don't know
their identities.

Without any inscription,
they remain anonymous.

The incoming
high-speed railway

is but the latest chapter
in the ongoing story

of the multi-layered
historical site

beneath St. Mary's Church,

one that may still contain
hidden secrets from the past.

In the eastern end of
Los Angeles, California,

about seven miles
southeast of Hollywood,

is the historic neighborhood
of Lincoln Heights.

Lincoln Heights is the
oldest suburb of Los Angeles.

In the late 1800s,

one of the city's first
horse-drawn streetcars

ran through its streets.

Due to the neighborhood's
proximity to downtown,

early residents here
were primarily commuters,

but Lincoln Heights quickly grew
into a community of its own,

attracting
manufacturing companies

and establishing both a nearby
hospital and a library.

In the early 20th century,

Lincoln Heights had
numerous attractions

that made it a destination
for Angelenos.

Families could visit
Lincoln Park,

one of the oldest parks
in the city,

and other amusements
like a merry-go-round

and miniature railroad.

Animal exhibits were
definitely a major draw here.

The Selig Zoo near the park

preceded the Los Angeles Zoo
by 50 years.

Lincoln Heights also featured
the California Alligator Farm

and even something called
the Los Angeles Ostrich Farm.

In 1931, planning
is underway for an orchard

on Lincoln Heights'
Flat Top Hill,

and a plumber at the site
discovers something unusual

while digging a trench
for the irrigation system.

It looked
like a vertebra

from some kind
of very big creature.

So a team from
the Natural History Museum

was brought in to investigate.

They found
a significant number of bones

buried under the ground.

The remains included a large
skull and lower jaw,

a left shoulder blade,
and a series of 22 vertebrae.

What was this thing?

3,000 pounds of bones
and sediment are removed

from the pit for further study.

And using a process
called relative dating,

the rock layers in which
the skeleton was entombed

are used to determine
the age of the fossil.

This area was part
of what's called

the Modelo Formation,

which dates to the Middle
to Late Miocene Epoch,

between 8 and 16 million
years ago.

Cross-referencing this data with
other fossils from California,

it was determined
this animal arrived

at its final resting place
over 10 million years ago.

This era was defined
by cooler global temperatures

after the warmer Early Miocene.

It was a volatile period
in the planet's history,

with dramatic geological changes

caused by shifting
tectonic plates.

Tropical forests declined
while grasslands expanded.

Geological studies
of the Modelo Formation

show that it was
submerged in the ocean

during this period at a depth
of about 3,200 feet.

The fossilized
remains are sent

for laboratory analysis,

and the results leave
researchers stunned.

They're from a previously

undiscovered species of whale.

This incredible specimen is
what's called a holotype,

meaning it's the only one of
its kind anywhere in the world.

It was given the name
Mixocetus elysius,

which was a reference to the
creature's whale-like features

and the geological layer
it was found in,

the Elysian Park sandstone.

Based on the measurements

of the skull and vertebrae,

it's estimated this whale was
approximately 32 feet long.

During this period,

it would have been one
of the largest in the world.

So its discovery raised
a couple of key questions.

How did an animal of this size
end up under the slopes

of Flat Top Hill
in Lincoln Heights?

And how did this creature die?

One of the most
terrifying sea monsters

from prehistoric times was a
giant shark known as megalodon.

Sometimes 60 feet in length and
weighing as much as 50 tons,

the megalodon was the largest
shark that ever lived.

It dominated the ocean as
the apex predator of its era.

So, could the Lincoln whale
have been a victim

of a megalodon attack?

Other whale fossil discoveries

suggest this could be
a possibility.

In 2022, fossilized
whale vertebrae recovered

along the Maryland shores
of the Chesapeake Bay,

showed evidence of a massive
compression fracture.

The fossils
were estimated

to be about
15 million years old.

And evidence showed that
the whale's backbone

had been forcibly bent
into a tight curve

that caused one of the vertebrae
to smash into another one.

That might actually be
a predation injury.

And what might have caused that?

Well, helpfully,
the tooth of a megalodon

was found with the remains.

In fact, it was touching
one of the vertebrae.

So is that what killed
our whale?

Sharks use
a variety of techniques

to disable their prey,

so if a megalodon had chosen
the Lincoln Heights whale

as its prey, it could have used
one of several methods,

including ramming it from below

or biting off its tail flukes
or pectoral fins,

neither of which were found
with the fossil.

The skull of
the Lincoln Heights whale

did show some trauma
near the jawbone,

but a 2024 report from
the Natural History Museum

stated there was no evidence
of any megalodon teeth

in the whale's skull, vertebrae,
or shoulder bones.

Yes, a megalodon could have
overcome the whale

without biting it, but there's
simply no concrete proof

that the Lincoln Heights whale
encountered a giant shark.

If the whale
wasn't annihilated

by a vicious predator,

it may have been the victim
of a silent killer.

Some of the most
insidious and lethal life forms

on the California coast are
harmful algae blooms, or HAB.

The single-celled algae,
Pseudo-nitzschia,

produce a deadly toxin
that can attack

the central nervous system
of marine mammals.

Those who ingest the algae
can experience seizures,

disorientation, fatigue,
and ultimately death

from neurological damage
or drowning.

The Cerro Ballena
fossil site

in Chile's Atacama Desert is
a strong point of comparison.

About 40 fossilized
prehistoric whale skeletons

from the Late Miocene
lay among remains

from seals and other
marine vertebrates.

The four distinct layers
of fossils were attributed

to recurring mass die-offs,

resulting from the presence

of large-scale
harmful algae blooms.

Studying an area
like Cerro Ballena

with multiple fossils deposited
over many millions of years

allows for a much more
robust theory

to develop around a mass death.

But evidence of one whale
carcass is much less conclusive.

Ultimately, it may be
next to impossible

to uncover physical
or chemical evidence

on the Lincoln Heights fossil

that proves it had
ingested toxic algae.

The greatest threat
to the whale may have been

the volatile habitat along
the California coast.

During the Middle
to Late Miocene period,

the tectonic plates
under California

were undergoing an incredible
transformation.

The Los Angeles basin
was especially active,

making catastrophic
submarine landslides

a frequent occurrence.

Paleontologists
believe that after

the whale perished,

it was buried in a violent
underwater landslide,

which would have immediately
concealed the carcass

from large scavengers

and helped preserve it
for millennia.

In 1976, a baleen whale fossil
from the Miocene period,

excavated in Poland, was
reported to have been found

in a similar state
of preservation.

Its death was
attributed to rapid burial

by quickly
accumulating sediment.

This supports the theory that
the Lincoln Heights whale

could have died from
a turbulent undersea event.

The Modelo Formation, in which
the whale fossil was found,

is largely made up of sediments

deposited by currents
in a deep sea environment.

Over the subsequent
11 million years,

great shifts
in tectonic pressure

along the California coast
raised the seabed by 500 feet,

pushing it 20 miles inland to
form the hills of Los Angeles,

where the Lincoln Heights whale
would eventually be found.

California's shifting
geological forces

may help explain the whale's
death and unusual burial,

but many unanswered
questions remain.

While it's possible
the Lincoln Heights whale

was subsumed by
a geological event,

the true cause of death
remains a mystery.

Old age, disease, or starvation

may have played a factor
in its demise.

More discoveries of any
fossil from the Modelo Formation

is gonna help paint a clearer
picture of what life was like

before this whale ever died.

One of the biggest unknowns

is why this whale fossil remains
the only specimen of its species

ever discovered.

With future excavations,
additional discoveries

will hopefully help us better
study the animal, its habitat,

and its history
during the Miocene.

For now,
Mixocetus elysius

is one of one;

a single piece of
a larger historical puzzle

that is yet to be
fully understood.