Original subtitles

[narrator] In Chile's Atacama Desert,

researchers uncover a grisly scene.

[Anthea] The man's skull showed evidence

of blunt-force trauma.

Is it possible he was the victim of a brutal attack.

In Luxor, Egypt,

a team of archaeologists discover ancient ruins.

[Anthony] As the excavation continued,

it became increasingly obvious

that this wasn't just a settlement,

it was an entire city.

So what was this place, and who built it?

In China's Taklamakan Desert,

explorers come across an extraordinary sight.

[Alison] They began finding vast areas

filled with carved wooden vessels

that looked a lot like modern-day canoes.

It wasn't until they looked more closely that they realized

these vessels weren't empty.

They were coffins.

Ancient lost cities.

Forgotten treasures.

Mysterious structures.

As new technology uncovers remarkable tales

hidden beneath the deserts of the world,

the secrets in the sand will finally be revealed.

The arid Atacama Desert

lines the coasts of northwestern Chile,

stretching north to south for over 600 miles.

It's the driest non-polar desert in the world.

The average rainfall is less than one inch per year,

and except for a few small springs,

there are no complete bodies of water

from the lower river in the north,

to the town of Chañaral in the south,

a distance of over 300 miles.

[Dan] The dry conditions of the desert

are exacerbated by a long history

of geological disasters.

Earthquakes, tsunamis, floods,

making this Pacific coastal area

one of the harshest environments on Earth.

But despite the brutal climate and conditions,

there's evidence of human settlement in the area

going back as far as 12,000 years.

They were mostly hunter-gatherers

who managed to adapt and survive

on the rich marine life the ocean provided,

such as fish, mollusks, birds,

and whatever mammals they were able to catch.

Over the millennia,

they developed tools to help the cause,

such as fish hooks and harpoons made from shells.

A team of researchers

funded by the Chilean government

is surveying a section of northwestern coastal Chile

when they make a startling discovery.

[Alison] It was a burial site

with a grave containing four skeletons

from roughly 3000 BCE,

dating to the Stone Age.

The desert conditions had kept the remains well-preserved,

so it was possible to identify them as two adult males,

one adult female, and one child.

[Dan] One of the adult male skeletons

was almost completely intact,

but it was positioned weirdly.

Both arms were pointing outwards

in different directions,

and one leg was extended away

from the rest of the body.

[Anthea] But it was the man's skull that really piqued curiosity

and offered a potential clue as to the cause of death.

The back of his skull showed evidence of blunt-force trauma.

Is it possible he was the victim of a brutal attack?

And if so, then who was the aggressor?

The Atacama Desert is filled

with the remains of those

who have suffered a violent death.

By roughly 1000 BCE,

a form of desert farming

had emerged in northern Chile

that frequently led to bloodshed.

There's evidence of farmers coming to severe blows

with gruesome results,

likely because the different communities

were all competing for the same limited resources

of water and fertile land.

[Alison] In one section of the Atacama,

the graves of 194 farmers

who lived roughly 3,000 years ago,

were excavated and examined

for markers of interpersonal violence.

Many of the skeletons had snapped ribs,

broken collarbones,

multiple facial fractures,

and, more telling, puncture wounds

in the groin, lung, and spine.

[Dan] The sheer brutality of these deaths

is an accurate reflection

of the kinds of conflicts we see around the world

whenever a society shifts

from hunter-gatherer to agrarian.

With that shift comes ownership of the land.

You get these classes,

you get wealth and disparity,

you have haves and have-nots.

You combine those social factors

with that environment,

with severe food and water scarcity,

and you've got a tinderbox

for deadly confrontation.

[Anthea] So it's certainly possible

that the traumatic injury found

on the adult male's skull in the Atacama

was the result of interpersonal violence

or a larger-scale conflict with a rival group.

It's not uncommon to find evidence

of such events in the region.

A team of scientists studying ancient Peruvian cultures

were surveying a section of the Atico River Valley

when they came upon an undiscovered burial site.

The grave held 24 people,

men, women, and children.

Analysis of the remains

found a number of physical injuries

to those bodies,

any of which could have resulted in death.

[Anthea] But the skeletons weren't alone in the grave.

They were buried along with elaborate grave goods,

such as ceramics, bones,

stone, and textiles,

dating to the early formative period

between 1800 and 1000 BCE.

This meant that the bodies had been buried

to a ritualistic standard

and with a significant amount of care and attention.

[Teddy] The combination of gruesome deaths

followed by careful burials

suggests their group was victorious

in some kind of conflict.

A win for their community would mean the victors

could bury their dead according to their traditions.

Is that what happened to the people discovered

in the Atacama?

But here's the thing.

Of the four individuals found at the Atacama site,

one of the skeletons exhibited injuries

associated with trauma.

And there were no grave goods found.

So it's unlikely that these people all died in a conflict

and were given a heroic burial.

An examination of the entire adult male skeleton

reveals another potentially violent cause of death.

[Teddy] A closer look at the blunt-force trauma inflicted on the skull

confirmed that whatever struck him,

did not kill him.

The wound had partially healed after the blow.

That doesn't rule out the possibility

of an interpersonal attack,

which he may have survived,

but there are additional injuries

to his body that point in another direction.

[Alison] The man has a broken rib cage

and is missing his cervical vertebrae

and both shoulder joints.

So he definitely suffered some kind of full-body trauma,

whether or not it killed him.

But if it wasn't the result of violence,

is it possible he was the victim of a natural disaster?

Chile is one of the most seismically

active places on Earth.

[Dan] In May of 1960,

the country suffered the most powerful earthquake

in recorded history,

registering somewhere between a magnitude 9.4 and 9.6.

The Valdivia earthquake shook southern Chile for 10 minutes,

killing over 1,600 people.

It also triggered a series of deadly tsunamis

that devastated several Pacific islands,

including Hawaii.

[Anthea] And it's not just a modern phenomenon.

The geological record of coastal Chile

contains evidence of powerful tsunamis

going back as far as 5,000 years.

So there's proof that natural disasters

were as much a threat to human life in prehistory

as they are today.

[Teddy] The Chilean coastline was also a casualty

of repeated deadly storms,

thanks to naturally occurring phenomena

called El Niño and La Niña.

They're the opposing extreme warm and cold weather patterns

that have a direct impact

on the surface waters of the Pacific

and can result in flooding,

wildfires, and vicious storms.

It's a pattern that has struck Chile

every two to seven years.

[Alison] The fact that the Atacama burial site

contains several bodies,

certainly supports the possibility

of a natural disaster.

Multiple burials have often been used in South America

to reconcile the sheer number of dead

after a single event casualty like an earthquake.

Samples from all four skeletons

are taken for comparison and diagnosis

by a joint team of Chilean and British researchers,

which leads to a breakthrough.

Samples from all four skeletons

are taken for comparison and diagnosis

by a joint team of Chilean and British researchers,

which leads to a breakthrough.

The bone marrow of the individual

with the skull injury

was filled with the preserved remains

of ocean life,

including tiny algae called diatoms.

The diatom test is used by forensic teams to determine

if an individual has died from drowning.

When someone drowns,

inhaled water filled with microscopic algae

can enter the bloodstream and travel throughout the body.

So even after the lungs collapse,

it can be transported into closed systems

such as bone marrow.

[Teddy] The fact that this one individual had diatom traces

of marine life in his bone marrow

confirmed he had indeed died from drowning.

Even more telling,

the other three skeletons' bone marrow

showed no traces of diatoms,

so death by drowning was ruled out for them.

[Alison] It was also determined

that he met his fate in shallow salt water.

He had swallowed a significant amount of sediment

in his final moments.

And sediment tends not to float in high concentrations

in deeper waters.

So the picture that emerged

was that of an accidental drowning,

as opposed to a natural disaster.

Further examination of the man's skeleton

provides another clue.

[Anthea] The wear-and-tear on his bones,

including marks on his arms and legs,

where the muscles had once attached,

showed the hallmarks of a repetitive activity

akin to a fisherman's tasks,

like rowing, harpooning,

and even squatting to retrieve a harvest of shellfish.

[Teddy] Based on this, it was believed

the individual died from accidentally drowning

in turbulent coastal waters while on a fishing venture.

The trauma to his rib cage and vertebrae

may have been caused by being thrown against the rocks along the shore.

And as for the mass grave,

there are a number of potential explanations,

including the possibility that the man was simply buried

along with other deceased family members.

The Stone Age Fisherman

is just one of Chile's many hidden stories

brought to life through a combination

of modern forensics

and good-old-fashioned deductive reasoning.

With the mystery now solved,

we have a greater understanding and appreciation

of the dangers of prehistoric marine life.

The city of Luxor stands

on the east bank of the River Nile,

surrounded by some of the most famous

archaeological sites in the world.

The region around Luxor could be considered

the world's greatest open-air museum.

The modern city is exactly where the ancient

Egyptian capital city of Thebes once stood.

Thebes was huge,

spanning about 36 square miles.

By 1500 BCE,

around 75,000 people lived here,

making it the biggest city in the world at the time.

Thebes was split into two halves,

a city for the living and a city for the dead.

The main part of the city

lay along the east bank of the river,

where administrative buildings, homes, and markets

were all built in clusters around huge temples.

The Theban necropolis lay on the west bank,

where royal tombs and mortuary complexes

covered more than three square miles.

The Theban Necropolis

is home to both the Valley of Kings

and the Valley of Queens.

This is where some of the most famous

archaeological discoveries of all time have been made.

One of these was in 1922,

when Howard Carter and his team

uncovered the tomb of Tutankhamun,

filled with extraordinary solid-gold grave offerings.

A team of archaeologists

searching an area near the Valley of the Kings

stumble upon an unexpected discovery.

The team had hoped to find an ancient mortuary complex

dedicated to Tutankhamun,

where his subjects would have placed funerary offerings

when he died.

But instead, they began to uncover

layers and layers of mud bricks.

It wasn't long before they realized they were walls,

spreading out in all directions.

[Amma] These walls were incredibly well-preserved,

sometimes standing up to nine feet high.

Behind them, they discovered various other structures

filled with objects of daily life.

There were homes,

what looked like administrative buildings,

and even a large bakery.

[Anthony] As the excavation continued,

it became increasingly obvious

that this wasn't just a settlement.

It was an entire city.

So what was this place,

and who built it?

The lost city stands beside another set of ancient ruins,

which may offer clues about its construction.

This adjacent site is huge,

spanning around 30,000 acres.

More than 3,000 years ago,

an enormous royal residence stood here,

built by the pharaoh Amenhotep III

as a show of royal and economic strength.

It was known as the Palace of Joy

and included huge living quarters for the elite,

as well as a temple dedicated to the god Amun,

and even a massive artificial harbor.

[Teddy] When Amenhotep III took the throne around 1386 BCE,

his empire stretched from the Euphrates to the Sudan

and enjoyed lucrative trade relations

with Asia and other territories in the Middle East.

As a result, he commissioned colossal building works

in and around Thebes,

including the palace and his own tomb complex,

parts of which still stand to this day.

So, could the lost city be one of Amenhotep's

massive construction projects?

Historical records from ancient Egypt

tell of a city called Dazzling Aten,

named after the Egyptian sun god,

and founded during Amenhotep III's reign.

Archaeologists had searched for this place for years

without any luck.

Maybe this legendary lost city has finally been found.

[Anthony] Many of Amenhotep III's construction projects

were stamped with his royal seal.

And we see this same seal on many of the bricks

used to build the curving walls of the lost city.

They also found colorful pottery, jewelry,

scarab amulets, and other artifacts

all marked in honor of Amenhotep III.

Given all of this,

we can assume that this lost city is in fact Aten,

finally uncovered after years of fruitless searching.

As excavations continue at the Aten site,

one object in particular stands out to the team.

[Teddy] Inside one of the ancient buildings,

they found a vessel

filled with 22 pounds of boiled meat

preserved for thousands of years.

The clay was stamped with the year 37,

which is roughly 1353 BCE.

This is right around the time

Amenhotep III passed on the throne to his son,

Amenhotep IV.

[Anthony] We know the two ruled together

as father and son for a short time,

because several structures inside Aten

show both of their names.

But then things suddenly changed.

[Amma] Many of the homes and workshops

look as though they were sealed up and left in a hurry.

This suggests that Amenhotep IV

left Thebes after taking power,

taking many of the residents with him.

But why would a young pharaoh leave a city

that had stood as the ancient Egyptian capital

for 150 years?

Clues to the pharaoh's sudden disappearance

lie in another archaeological site,

over 150 miles north of Aten.

Here on the outskirts of a large desert bay,

archaeologists have long studied intriguing hieroglyphics

carved into the surrounding limestone cliffs.

European travelers first noticed these carvings

in the early 1700s,

but it took over 100 years

before they were finally translated.

When we were able to read them, it became clear

that they were boundary stelae,

monuments built by the ancient Egyptians

to mark the edges of towns and cities.

There are 16 boundary stelae here,

with the largest measuring over 25 feet high.

They tell the story of a pharaoh on an unusual mission,

to build a city dedicated to one god only, Aten.

According to the stelae,

this city once held temples,

mansions, and tomb complexes

all dedicated to Aten.

who is most often depicted as a solar disk.

[Anthony] The dates on the stele line up with Amenhotep IV's reign,

but his name is nowhere to be seen.

Instead, they address the pharaoh as Akhenaten.

Could there have been two rulers overseeing Egypt

at the same time?

The answer lies in the beliefs

of a surprisingly radical and progressive ruler.

[Alison] Amenhotep IV was a cultural revolutionary.

During his reign, he developed

an entirely new artistic movement,

where the stiff, two-dimensional silhouettes

we commonly associate with ancient Egypt

gave way to more naturalistic portraits

with elongated features.

But his main concern was with religion.

[Teddy] For over 3,000 years,

ancient Egyptian rulers and their subjects

worshipped a whole pantheon of gods.

They had over 2,000 deities.

Amenhotep IV decided he wanted to do away with

all but one of these gods,

the solar disk, Aten.

[Amma] He was so devoted that he even changed his name

from Amenhotep IV to Akhenaten,

which roughly translates to "In Service of Aten."

Part of his mission to revolutionize

ancient Egyptian religion

meant discarding his father's legacy

and moving the capital city away from Thebes

to a new city,

and he succeeded.

[Anthony] The new city marked by the boundary stelae

was named Akhetaten, or Horizon of Aten,

and was built around two huge temples dedicated to Aten,

as well as the king's royal residences.

The names of all other deities were erased from temple walls,

and household altars were built for residents

that showed the royal family worshiping Aten.

It would have taken a lot of effort

to actually change deeply held Egyptian beliefs

this radically.

So the crucial question is,

did it work?

Despite the pharaoh's best efforts,

a series of archaeological discoveries

point to a growing sense of dissatisfaction

among his people.

Akhenaten's father was a master of diplomacy,

but his son was anything but.

In 1887,

a local woman discovered a cache of 300 clay tablets

engraved with cuneiform writing.

Analysis found that these were actually letters

written during Akhenaten's rule

and exchanged between Egypt's royal court

and the neighboring states.

These are filled with complaints about Akhenaten,

from foreign rulers complaining about the quality of his gifts

to his lax attitude towards his military.

Even Akhenaten's own subjects pushed back against him.

Members of the religious elite were incredibly upset

with the erasure of many of their gods,

and ordinary citizens secretly defied the orders

to worship just one god.

One especially shocking discovery

brings Akhenaten's unpopularity into even sharper focus.

[Alison] Akhenaten had left specific instructions for his burial

in a set of royal tombs carved into the rock,

surrounding Akhetaten.

The walls were decorated

with reliefs of his family worshipping Aten,

rewriting typical Egyptian funeral rituals.

The tombs were forgotten for thousands of years,

but when archaeologists finally began excavating,

they found that the illustrations

had been defaced

and the pharaoh's sarcophagus

had been smashed.

To this day, we can't be sure who was responsible

for the destruction of Akhenaten's tomb,

but there is a suspect.

Akhenaten's son was none other than Tutankhamun,

who inherited the throne at only nine years old.

Throughout his 10-year reign, he went to extreme lengths,

to cut his father out of Egyptian history.

He relocated the capital back to Thebes

and reinstated the old gods.

[Amma] Tutankhamun's efforts were incredibly successful,

and only when the ruins of Akhenaten were discovered

did we learn the true extent of his father's troubled legacy.

While we don't know for sure,

it seems that smashing Akhenaten's tomb

was part of this erasure.

To this day, the whereabouts of his mummy

are still unknown.

The lost city of Aten

and the ruins of Akhenaten

stand as powerful time capsules,

allowing archaeologists to reconstruct

the tumultuous power dynamics between three generations

of infamous ancient Egyptian kings.

In the southern part

of the Xinjiang Uyghur Autonomous Region

lies a vast depression

known as the Tarim Basin.

The Tarim Basin

is one of the most landlocked places in the world.

It's almost as far from the ocean as you can get

anywhere on Earth.

And right in the center of that basin

lies the Taklamakan Desert,

which stretches 130,000 square miles.

That is bigger than the entire state of New Mexico.

Huge mountain ranges

block almost all rain from the desert,

making it one of the driest places in the country.

In the central region,

an average of only ten millimeters of rain

falls each year.

European explorers making their way through the unforgiving Taklamakan

come across an extraordinary sight.

[Alison] They began finding vast areas

filled with carved wooden vessels

that looked a lot like modern-day canoes,

the last thing you'd expect to find in the desert.

Stranger still,

the vessels were often accompanied

by what looked like oars, stuck into the earth

so they pointed straight up to the sky.

It wasn't until they looked more closely

that they realized these vessels weren't empty.

They were coffins.

[Anthony] These sites are actually massive graveyards,

some containing hundreds of bodies.

The burials span over 2,000 years,

with the earliest dating back to 2100 BCE.

The bodies are incredibly well-preserved,

so much so that some mummies were found

with their eyelashes still intact.

Unlike a lot of other cultures

that mummified their dead on purpose,

using elaborate rituals and chemicals,

and all this other stuff,

the mummies here

are just a byproduct of the environment.

It's so dry in the desert

that, basically, it just stops the decomposition process

leaving behind these extraordinary

mummified remains.

[Anthea] One thing that really stuck out

was that many of the mummies

seemed to have had blonde or red hair,

blue eyes, and stood well over six feet tall.

Because these features are typically found

in populations farther west,

debate immediately sparked

about where these people came from.

Could they have traveled here?

If they had,

where did they come from?

Intriguing objects

buried alongside the Taklamakan mummies

provide glimpses into their lives.

The mummies were buried with numerous grave offerings,

including grains such as wheat,

barley, and millet.

Also found were the bones and horns of herd animals

like cows, sheep, and goats.

Some people were even buried with pieces of cheese

hung around their necks.

We can't be exactly sure

why these grave goods were left behind.

It could be that they were offerings to some sort of deity

or that they might accompany the dead into the afterlife.

Based on the animal remains,

these were probably successful farmers,

raising flocks of various animals

they could use for food and for hides.

In fact, many of the coffins

have animal skins stretched over them,

possibly to protect the body.

The evidence of livestock leads experts to wonder

whether the Tarim Basin mummies

may have descended from ancient nomads.

The Yamnaya people were an incredibly powerful culture

that mastered animal husbandry roughly 5,000 years ago.

Over time, they began migrating east en masse,

sweeping across Europe

and interbreeding with various other cultures.

In the span of a few centuries,

they made up about half of the genetic makeup

of Central Europeans.

[Dan] There were also the Afanasievo people

who farmed herds of cattle and sheep and horses

in the Altai Mountains, and eventually

spread all the way across Siberia and Mongolia.

They're sometimes considered

an eastern offshoot of the Yamnaya.

Could another wave of migration

have taken them farther south into the Tarim Basin?

That scenario seems unlikely

when you look at funerary practices.

The Yamnaya would typically inter their dead in pits

that were then covered by wooden planks

and earthen mounds called kurgans.

The Afanasievo rituals also involved

building these impressive kurgans

on top of the deceased.

These would then be surrounded

by a ring or a square of stones.

There's no evidence to suggest

that the Yamnaya or Afanasievo

ever interred their dead in boat-shaped coffins,

so it's not likely that the Tarim Basin mummies

belonged to either culture.

In the search for information about the mysterious burials,

experts turn to one of the mummies' most surprising features,

their clothing.

Thanks to the incredible preservation,

we can even see how well-dressed

some of these mummies are.

One example of that that stands out

is the man from Hami.

He was found with a spectacular collection of hats.

[Anthea] The man from Hami isn't the only Tarim Basin mummy

famous for headwear.

In the lost city of Subeshi,

a group of women were discovered,

all buried wearing tall, pointed black hats.

Today, they're known as the Witches of Subeshi.

The textiles from both of these sites

reveal potential clues

about where these people may have come from.

Among the fabrics recovered

from the burial of the man from Hami

were plaids that were made using a diagonal twill weave.

These fabrics match those found in Celtic sites around Europe,

dating from approximately the same period.

[Alison] The hats found with the Witches of Subeshi

also echo European fashions,

like the tall-pointed hats called hennins.

These similarities beg the question,

how could these trends have reached the Tarim Basin?

Did Europeans migrate here?

Are the mummies of European descent?

The answers may lie in one

the world's most famous trade routes.

[Dan] People often talk about the Silk Road

as though it's this one highway

that used to be there, but it wasn't one road.

It was a vast network of routes that stretched over 4,000 miles,

and it linked the powerful civilizations

of Rome and China.

It emerged about 130 BCE,

and for over 1,500 years,

traders used it to carry silk to the west

while textiles and precious metals

went to the east.

[Anthea] The Silk Road cut through some of the most

imposing landscapes in the world,

including the Gobi Desert,

the Pamir Mountains,

and, crucially, the Tarim Basin.

Could the Silk Road be connected to the mummies?

A team of international researchers comes together,

determined to devise a study

that could reveal where the mummies came from.

Using tooth and bone samples from 13 of the Tarim mummies,

they set out to conduct a thorough genomic analysis,

the first such analysis

of any prehistoric population in the region.

Genomic studies

look at a person's entire genetic makeup

rather than individual genes.

These data are then compared to those from other populations

to understand how any given sample

fits into the grand scheme of human history.

The samples taken from the mummies

were compared to several sets of ancient DNA,

as well as to modern populations.

And contrary to earlier theories,

the genomic study proved

that these people did not migrate

to the basin from Russia or Europe.

They were, without a doubt, local.

[Dan] Not only were they local to the Tarim Basin,

the mummies had links to the land

going back nearly 200 generations.

And the study also found

that these people were extremely inbred.

Mummies found in cemeteries almost 250 miles apart

shared DNA as closely as siblings would.

[Anthea] Given their location, it's very possible

that these people came into contact

with merchants traveling along the Silk Road,

which meant access to goods

from all over Europe and Asia.

And this would explain the textiles found

in some of the graves.

And despite not intermarrying with these travelers,

it seems as though the Tarim people

were welcome to their ideas

and maybe even their fashion trends.

The Tarim Basin culture was a population

that was genetically isolated,

yet still open to outside influences.

They stand as an extraordinary example of a people

who seemingly welcomed cultural exchange

while maintaining their own unique traditions.

Built atop of series of hills,

the city of Jerusalem stands

between the arid mountains of Jordan to the east

and the coastal plains

of the Mediterranean to the west.

During spring and fall,

the city is beset by a particularly strong wind,

known as the khamsin.

[Anthea] The khamsin is a hot, sand-filled windstorm

that usually blows in from the southeast.

It can reach temperatures of up to 104 degrees

and blow continuously for up to four days.

It gets its name from the Arabic word for 50,

because the winds tend to come

within the same 50-day period each year.

[Amma] Jerusalem is considered

one of the oldest continuously inhabited cities in the world.

Around 5,000 years ago,

the first Canaanite settlements appeared in the area

before it was conquered and renamed the City of David.

In the early 16th century,

the Ottomans constructed what we now call the Old City,

a walled enclave built just north

of the original City of David.

Over time, modern Jerusalem

expanded around these two ancient centers,

blending thousands of years of history

into the city we know today.

In the district of Silwan,

among the ruins of the City of David,

a group of archaeologists

makes a surprising discovery.

[Teddy] They were working at a site known as the Givati Parking Lot,

the most extensive archaeological dig

in all of Jerusalem,

and were hoping to find the oldest remnants

of the City of David

when they came across a totally unexpected structure.

[Amma] There, carved right into the bedrock,

was an enormous trench.

The cut section was massive,

between 20 and 30 feet deep,

and around 115 feet wide.

The neat, steep sides and even dimensions made it clear

that this depression was no natural feature.

It was dug by hand.

But just what was this enormous cut in the bedrock?

This mysterious trench

isn't the only enormous structure

dug into the bedrock beneath Jerusalem.

Along the southern slope of the City of David

lies an ancient reservoir

known today as the Pool of Siloam.

[Anthea] During the Bronze and Iron Ages,

the City of David was the core of ancient Jerusalem.

It was built on a narrow, elongated plateau

leading down to the Kidron Valley.

For thousands of years,

the residents depended on this valley,

because it was home to the Gihon Spring,

the city's primary water source.

[Teddy] Around 3,000 years ago,

the city was ruled by King Hezekiah,

who oversaw a time of immense political turmoil.

He took part in a series of revolts in Palestine

that gained support in Egypt and threatened the rule

of the Assyrian king, Sennacherib.

He knew the Assyrians would be out for revenge

and that fortifying the city would be crucial

in repelling their attacks.

[Amma] The Gihon Spring just outside the city walls

was especially important from a tactical point of view.

If an army did invade,

the water supply from the stream

would be key to supporting the attacking soldiers.

To cut off the water supply from the Assyrians,

Hezekiah cut a tunnel

through nearly 2,000 feet of bedrock

to redirect water from the spring

into a large reservoir behind the city walls

called the Pool of Siloam.

[Anthony] The original Pool of Siloam was roughly 53 feet long,

but over the years, it was expanded to 225 feet.

Could the trench found in the ruins nearby

have been a part of this enormous water feature?

Or could it have acted as another reservoir,

keeping water flowing to the city's population

even if it came under siege?

A reexamination of previous digs in the area

leads to a breakthrough.

[Teddy] It turns out this latest discovery

was part of a larger pattern.

In the 1960s, a British archaeologist

working to the east of the Givati Parking Lot

discovered a similar ditch carved into the earth.

Several decades later, in the early 2000s,

a different team working farther north

discovered yet another area that had been sliced through.

[Amma] When we piece these discoveries together,

it suddenly becomes clear

that this isn't a series of trenches.

What we're looking at are different sections

of a single enormous moat.

Based on the existing evidence, it seems likely

that it once extended the entire width of the ridge

of the City of David.

Moats have historically been built

as a defense mechanism.

Could this be the case here too?

90 miles north of Jerusalem

lies the Tel Hazor archaeological site,

where a similar structure provides a possible clue.

During the Bronze Age and into the Iron Age,

Hazor was one of the largest

and most prosperous cities in the region.

The city was located on a crucial trade route

connecting Egypt, Syria, and Babylon,

which allowed it to expand quite rapidly.

Estimates suggest that at its peak,

up to 40,000 people may have lived here.

[Teddy] But despite its importance,

Hazor was lightly fortified and vulnerable

to potential invaders.

To protect themselves,

the ancient Canaanites built a wall around the city

and fortified it with a deep, steep-sided moat.

[Amma] Similar city walls and defensive moats

have been uncovered in other ancient cities in the region,

including Samaria and Jezreel.

Together, these discoveries suggest that defensive moats

were a fairly common feature of urban fortifications

during the Bronze and Iron Ages.

Could Jerusalem's moat be part of this same tradition?

The keys to unlocking the mystery

of the Jerusalem moat

may lie in the city's unique geography and layout.

[Anthony] Most ancient cities are built on hills

that rise high above the surrounding land.

And in part, this was a military strategy.

If an army were to attack,

defenders of the city would be able to see the soldiers coming

from as far away as possible.

[Anthea] Jerusalem's planning and layout are radically different.

The city is on a narrow ridge

that slopes upwards from south to north.

Ancient Jerusalem

lay on the southeastern part of the ridge,

downhill from the highest point.

This was likely because the city depended so heavily

on the Gihon Spring,

which lay in the Kidron Valley nearby.

This configuration made the city vulnerable to armies

coming from the north who would have the advantage

of attacking from a higher point of elevation.

[Teddy] The moat lay on the northern side of the city,

between the residence and the highest point of the ridge.

With a width of roughly 115 feet,

this single addition would make the city

significantly harder to invade.

If armies were to attack from above,

they would find themselves trapped and helpless,

allowing Jerusalem's military to pick them off

before they could reach the city walls.

Despite compelling evidence

painting the moat as a defensive structure,

doubt still lingers.

While it makes sense to build a moat here

to protect the ancient core of Jerusalem,

we can't know for sure

whether or not this was its true purpose.

Many mysteries still remain

surrounding this ancient structure,

including when it was built.

While it seems to have been in use by the 9th century BCE,

there are very few clues as to when it was first dug.

[Anthony] And what's more,

the moat might be part of a much larger

and far more intricate complex that we have yet to uncover.

Two sets of strange, smoothly carved rock channels

have also been found in the Givati Parking Lot.

And based on their location,

they may have once connected

to the royal administrative quarter

during the Iron Age.

So the moat may have a connection to these channels,

but their exact purpose remains a complete mystery.

[Anthea] What we do know is that

as the city of Jerusalem expanded across the ridge

and crept northwards,

the need for the moat eventually disappeared.

When it came time to build outside the ancient city walls,

residents seemed to have filled in the huge structure,

burying it for thousands of years,

only for it to be now rediscovered.

As work continues at the Givati Parking Lot,

researchers continue to piece together

the geography of ancient Jerusalem,

unearthing ruins that raise just as many questions

as they answer.