All language subtitles for The.UnXplained.S06E01.720p.WEB.h264-EDITH

A vast subterranean chamber

hidden for centuries.

A legendary lost treasure
buried in an ancient mine.

And a town
in the Australian Outback

that is located
entirely underground.

For as long as humans
have walked the Earth's surface,

we've also wondered about

what lies beneath our feet
deep underground.

Are there profound secrets
about our planet

buried beneath layers of rock,
or hidden in vast caves?

What can the subterranean world

tell us about humanity's past,

and perhaps even its future?

Well, that is what
we'll try and find out.

Human beings
have a strong desire to learn

everything we can about
the planet that we live on.

After all, we've launched
satellites into outer space

that have photographed
every inch of the Earth's surface,

and we've used
deep-sea submarines

to journey to the
bottom of the ocean.

However, there is one
final frontier in our world

that remains almost
totally shrouded in mystery.

For we have yet to fully explore
the vast underground depths

of our planet Earth.

It's really uncommon for someone
to know how deep the Earth is.

Very smart people often
guess, "hundreds of miles?"

When in fact, it's 4,000 miles
to the center of the planet.

L.A. to New York is
just a fraction of that,

with the 2,700 miles.

The mass of the Earth is great.

And when you think
about the amount of rock

that's piled on rock, on rock,

that pressure is incredible and
prevents us from going deeper.

So, what's beneath our feet?

We don't know.

Mankind's relationship
with the underground

stems from our innate curiosity,

and the ground beneath our
feet is open season for that.

Today, scientists
and explorers are compelled

to investigate the
subterranean world,

in hopes of shedding new light
in the darkness of its depths.

But these efforts are
just the latest chapter

in humanity's long
quest to learn more

about all that we
cannot see beneath us.

In fact, our fascination with
the secrets of the underground

stretches back
thousands of years.

Going back 3,500 years, we
find drawings and paintings

underground where
it's completely dark.

So, we can see how
our early ancestors

connected mythology
to the underground,

in terms of their
relationship to the Earth.

These explorations and forays

meant something
on a spiritual level.

They were pushing
as far as they could go

with the technology
that they had.

The
underground has always been important

in human history,
and it's tantalizing

but it's also kind
of frightening.

For instance, we can look
to Hades in Greek mythology,

this underworld
which is a metaphor

for not being blessed by
the light of the heavens.

Also, we can look to Dante

going into the seven
circles of Hell in an Inferno.

All of these point to
an underground space

that you'll go into and
never come out from.

While often
described as a place of danger,

darkness and doom in
the legends and folklore

of cultures around the world,

it was during the
18th and 19th century

that the perception of
an underground world

became less mythological
and more scientific.

This evolution in thinking
is perhaps best illustrated

in author Jules
Verne's seminal novel

Journey to the
Center of the Earth,

which was published in 1864.

Jules Verne's
Journey to the Center of the Earth

is the story of a professor,
his nephew and their guide

going into the
center of the Earth

through a volcanic
crater in Iceland...

making their way through
these subterranean passages

and finding
prehistoric plant life

and creatures and
maybe even a suggestion

of some sort of
humanlike creature

that they glimpse
but don't interact with.

Jules Verne was
a well-read author,

he was up on the
science of the day,

and he made a
really scientific effort

at describing an entire
subterranean world.

It's a fictional book,

but it really resonated
with people's imaginations.

Journey to
the Center of the Earth

had a profound effect not
just on science fiction readers

but also on actual scientists,

who were inspired to explore
deeper than ever before.

By the 20th century,
modern drilling technology

gave scientists a
new tool for satisfying

our ongoing curiosity
about what lies underground.

The most famous effort to drill
into the planet started in 1970,

when the Soviet Union
embarked on an ambitious attempt

to reach as deep as
possible into the Earth.

The project, which was conducted

on the Kola Peninsula in Russia,
lasted for more than 20 years,

and resulted in
what is referred to

as the Kola Superdeep Borehole.

The hole, which
is nine inches wide,

reaches an astounding
7.6 miles into the Earth.

The Kola Superdeep Borehole

is just a really
thin, narrow hole

straight down into the Earth.

One of the reasons why
they made the hole that shape

is that the wider the space
it is that you're drilling,

the more resistance
that you run into.

One of the biggest obstacles

to digging that hole was
the temperature increases

about 60 degrees Fahrenheit

for every kilometer
that you go down.

These teams found, when
they were drilling down,

that the rock started
to behave like plastic.

And that the solid rock
was actually gumming up

the works of-of their drills.

There's so much pressure there,

there's so much
heat there, eventually,

they could drill no deeper
and they had to abandon it.

And since then,

there has been no project
that has gotten deeper.

It's actually the deepest
hole that has ever been drilled

to this day by humans.

While the
Kola Superdeep Borehole

is an inspiring
feat of engineering,

at 7.6 miles in depth,

it only reaches less
than one percent

down to the center of the Earth.

And in fact, many
experts believe that instead

of using drills to dig
into the underground,

we should instead listen

to subtle vibrations
in the earth

that are called seismic waves.

By studying seismic waves,

scientists detected
two giant structures

deep inside of
the Earth's mantle.

These formations
are so oddly shaped

that they are commonly
referred to as "Earth blobs,"

and according to experts,
Earth blobs pose a dire threat

to the survival of humanity.

These blobs are massive.

Hundreds of miles tall,
the size of continents,

very irregular in shape,
and they're very hot.

The temperature of
the surface of the Sun

is the temperature
of these things.

There's the possibility
that over time,

these blobs might rise

and come to the
surface and would result

in crazy intense
volcanic eruptions.

The gigantic energy

from a volcano comes
from underground,

underground from the
core of the Earth itself,

creating a catastrophe
beyond human comprehension.

And so, when it comes to
what's underneath our feet,

we have to watch out.

It's staggering to think

that we've only managed to drill

less than one percent
into the Earth's crust.

But even so, archaeologists
continue to make

shocking underground
discoveries all the time,

such as a baffling man-made
cave system in China

that was carved
thousands of years ago

by a mysterious
unknown civilization.

In a small village,

a group of farmers begin
draining several ponds

to create space for
new planting fields.

But as the waters recede,

they make a
remarkable discovery.

The villagers saw

the water was slowly going down

and there were steps going down.

So, they got very
excited that this was

some kind of, you know,
archaeological discovery.

And when they went inside,

they found that
they were in a group

of underground man-made caverns.

Once the water
was completely drained,

the villagers discovered a
series of astonishing chambers

that had been carved
underground centuries earlier.

Further excavations
revealed the existence

of 24 massive caverns.

Each cavern covers
an area of approximately

11,000 square feet,

or roughly the size
of two mansions.

Archaeologists have also
noted that the walls, pillars

and ceilings of the caverns
were all precisely carved

to have an unusually smooth
and symmetrical appearance.

All told, the massive
underground complex

measures 320,000 square feet,

which is the size of more
than five football fields.

These incredible
man-made structures

are collectively referred
to as the Longyou Caves.

The discovery of
the Longyou Caves

is very fascinating

because there was
absolutely nothing to suggest

that there were these
carved, beautiful caves

actually beneath the water.

And so, when the actual
caves were discovered,

everybody was absolutely amazed

because there was no
indication that they existed.

They have these
pillars inside them

which are anything
up to 100 feet in height.

And there are long corridors.

There's some beautiful
relief carvings on the walls

of animals and dragons
and things like this

that are of immense
sophistication

in their design and the
manner that they were carved.

When you look at the
carvings, the chisel marks are so uniform,

there's very detailed
shaping of some of the stones.

To the untrained eye, it
looks like something created

in the last 20 or 30 years.

Some people suggest the caves

are one of the Wonders
of the Ancient World,

but they weren't
discovered until 1992.

So this raises so
many questions.

Based on
the carvings on the walls

and artifacts recovered
in the chambers,

archaeologists estimate that
the extraordinary Longyou Caves

are roughly 2,000 years old.

While there are similar
ancient underground structures

throughout China,

the size and sophistication of
the Longyou Caves is unique.

But just who exactly carved
these enormous caverns

and why remains a mystery,

because there is no
mention of this site

in the historical record.

How is it possible that
the existence of 24 caves

can go unrecorded?

This is very strange
because the Chinese

have always been very meticulous

in the way that they've
recorded provincial data.

And yet, there was
absolutely nothing,

no mention whatsoever
of these caves.

The caves
themselves are so massive,

such a huge undertaking.

It's not something that
a bunch of local villagers

might have done for a hobby.

We can estimate that
it would have taken

a thousand people,
working 24 hours a day,

six years to carve
out these caverns.

There ought to be some
kind of geographical feature,

some kind of odd-looking
hill or an infield valley

or something where all
that sandstone has gone,

but we don't know where that is.

In recent years,

some historians have
suggested that the Longyou Caves

disappeared from history
because they were intended

to be secret caverns

that were never
meant to be found.

We do not know
who built the caves.

But we can guess,
considering the fact

that they're 2,000 years old,

that they were built in a
period called the Warring States.

And at the time,
China was a patchwork

of different kingdoms
all fighting each other.

And the fact that they are not
mentioned in ancient documents

could well be a
factor of their use

for some kind of
strategic purpose.

So, "We're not
gonna tell the enemy

"where our secret bunkers are.

We're not gonna tell them
where our secret supplies are."

Could the Longyou
Caves have been a subterranean place

to hide critical supplies

or even people from
encroaching enemy forces?

Or could their purpose
be tied to the deep waters

that shrouded their location?

What's interesting
about the Longyou Caves

is it seems that
when they flooded,

the water helped maintain
the structural integrity.

Somehow, it took the
load off some of the beams,

for example,
holding up the roofs.

Now that the caves
have been drained,

the Chinese have
been obliged to add

extra buttressing
to hold them up.

And so, I think they were

a storage facility,
um, and I think,

certainly, many of them
were intended for water.

The area is drought-prone,

so in the event of some
kind of military crisis,

it would have been very
handy to have a secret base

with enough water for
them to live on for years.

Were the Longyou Caves
hidden beneath a pond for centuries

because they were built to
be a secret water reservoir?

Or could they have
had another purpose,

that has yet to be unearthed?

For now, the answer
remains lost to history.

But in modern times,
the caves have become

an important source of pride
for the people of Longyou,

who regularly hold festivals in
this ancient underground space

to commemorate their heritage.

The story of the Longyou
Caves is actually very fascinating

because it would
seem that by looking

beneath the earth itself,

we're obviously going to
discover many, many caverns,

underground
chambers or even cities

done by human hands that
have been completely lost,

and that's a very
exciting prospect.

Archaeologists are
conducting ongoing excavations

in an attempt to
unravel the mystery

of who built the incredible
Longyou cave system.

But some experts believe
the best way to solve

an underground
mystery is not by digging,

but rather by researching
historical texts.

For instance,
there's a copper mine

in southern Israel that,
according to the Bible,

may have been the hiding
place of King Solomon's treasure.

In the
deserts of southern Israel

lies a mountainous region
that is called the Timna Valley.

Today, this area is known

for its uniquely
shaped sandstone cliffs.

But more than 3,000 years
ago, the Timna Valley was the site

of a vast network
of copper mines.

In the Timna
Valley, mining activity took place

for a long, long time,

and most of the
mining operations

took place underground.

The deepest is about 115 feet.

They would hew in the
ground circular shafts,

and going down that shaft,

they would cut steps
into the side of the shaft.

And they would tunnel
along horizontally,

where they would
extract the copper

and take it back
up to the surface.

In recent years, the
Timna mines have attracted attention

because there are
those who believe

that buried underground
in one of these deep tunnels

is the legendary lost treasure
of the biblical King Solomon.

In the Old Testament
of the Bible,

King Solomon is
described as a noble

and wise ruler of Israel.

Historians believe that
Solomon was a real person

who lived in the
10th century BC.

King Solomon is
an intriguing figure

because the Bible makes
so many claims about him

controlling vast
amounts of territory.

According to the Bible,

Solomon expanded
ancient Israel considerably,

from the Euphrates
river in the north

all the way to the
River of Egypt,

and so, a much more
expansive territory.

The Bible also describes

Solomon controlling
vast amounts of wealth.

Solomon decides to build
a temple, in Jerusalem.

The temple becomes
the home of God,

and he spares no expense.

And he was so committed

to having the best
temple in the region

that he actually imports
the finest materials

to build this temple.

According to the
Bible, Solomon's temple was built

from the best limestone
and cedarwood.

Inside, the walls were
overlaid with pure gold,

and Solomon adorned the temple
with objects made out of copper,

which was also a
precious metal at the time.

King Solomon ruled
Israel for 40 years

before dying in 931 BC.

Upon his death, Solomon
reportedly left behind

an enormous amount
of gold and other riches

in his magnificent temple.

But then, in 586 BC,

the Babylonians
invaded Jerusalem

and sacked Solomon's temple.

When the Temple of Solomon
was destroyed in 586 BCE,

all the temple treasures
were lost to history.

An ancient legend says
that Solomon's treasures

were taken out of
Jerusalem and buried.

There are those who
believe that the treasures

are, to this day, still hidden.

For centuries, the
legend of King Solomon's lost treasure

has been a source of
fascination and mystery.

In 1885, the story was
exposed to a wider audience

when author H. R. Haggard
wrote his famous novel

King Solomon's Mines,

which speculated that
Solomon's treasures

were hidden deep in an
underground mine shaft.

But if there is some
truth to this legend,

then where is King
Solomon's treasure buried?

For some, the most likely
location is the Timna mines.

The Timna Valley is located

not more than 150
miles from Jerusalem.

So we're talking
about close proximity.

At Timna, there are 10,000
mine shafts, maybe more,

and so, it's easy for
people to kind of say,

"There must be a connection."

In the last several decades,

numerous researchers have
tried to prove that the Timna mines

are, in fact, the hiding place

of King Solomon's
lost treasures.

Some of the first evidence
in support of this theory

was found by an archaeologist
named Nelson Glueck,

who conducted a series
of excavations at Timna

in the 1930s.

Nelson Glueck

made a huge study of
the-the copper mines,

the smelting works,

and also, the camps
of those that were there.

And what he found under
the ground was pottery

dating from the 9th
to 10th century BC.

And this was the
exact time frame

of the reign of King Solomon.

And so, for Nelson Glueck,

he felt that he had discovered
evidence of Solomon's mines.

Nelson Glueck's discoveries

made sensational
headlines around the world.

However, despite
years of searching,

Glueck was unable to
locate the fabled treasure,

and some experts began to
think that Glueck was wrong

to associate the Timna
mines with King Solomon.

But then, in 2019,

a team of archaeologists led
by Professor Erez Ben-Yosef

of Tel Aviv University,
made a remarkable discovery.

While excavating an ancient
mining worksite at Timna

that is referred
to as Slaves' Hill,

they found more evidence
that links this location

to King Solomon.

When you take
the totality of this,

the Bible and what it
says about King Solomon,

the presence of these copper
mines in the deserts of Israel,

and put all these
elements together,

for people of faith,

it gives them a
greater assurance

of the truthfulness
of the Bible,

that it involves real people

in real places in a real time.

Is the treasure of King Solomon

hidden somewhere in
the Timna copper mines?

Experts continue to search
for clues deep underground

in hopes of answering
that long-standing question.

Not unlike another
subterranean mystery

that has also
persisted for centuries.

One that involves
the strange theory

that there are vast open spaces

located in the
center of the Earth.

Seismologist
Dr. Paul Richards

and his team at
Columbia University

make a remarkable announcement.

They discovered that
while a full rotation

of the Earth's surface
takes 24 hours,

the iron core at the
center of our planet

actually spins faster.

They were measuring

the rotation of the
core of the Earth

in relation to the
surface of the Earth,

and what they found
was that it's not constant.

And it leads people to believe

that there is a disconnection
between the two.

Maybe it's not molten rock.

It could be open air.

So, when you put all
of that data together,

it leaves open the idea,

the hypothesis,
that Earth is hollow.

Could there really
be vast hollow space

beneath the Earth's surface?

It sounds crazy.

And yet, for thousands of years,

the belief has persisted
that beneath our feet

there are not just
caves and tunnels

but an entire underground world.

The idea of the Hollow
Earth is that we live on a shell

and that inside the
Earth is a hollow cavity

with its own atmosphere,
its own animals,

and possibly, its
own inhabitants.

The concept of a Hollow Earth

goes well back
before written word.

We have pictograms,

cave drawings,
things that describe

either deities coming
out of the Earth

or man trying to communicate
with deities in the Earth,

and that's where the idea
of a Hollow Earth came from.

Of all the ancient
tales about Hollow Earth,

perhaps the most intriguing

is one that involves
the Garden of Eden.

There is an ancient legend

that is recorded from
a very, very old text

called the Sefer HaTemunah,
the "Book of the Image."

The legend tells us

that a cave called Machpelah

is the doorway to
the Garden of Eden...

which exists in inner Earth.

But here's the
interesting question:

a garden in a cave?

It doesn't work like that.

Gardens have plant life
that grows, requires sun.

But in inner Earth,
there's an inner sun.

Could Adam and Eve have lived

in a lush paradise
deep underground?

The incredible
notion that people

could inhabit
subterranean spaces

has been embraced
not just in ancient times

but also, in the modern era.

In fact, by the turn
of the 20th century,

the fascination with
Hollow Earth was so strong

that a new generation
of scientists and explorers

set out to find proof
of the existence

of a so-called "Inner Earth."

Perhaps the most
fascinating of those expeditions

was led by an
American Naval officer

named Admiral
Richard E. Byrd in 1926.

Admiral Richard Byrd

was a famous American
aviator and explorer.

And he claimed that
on one of the journeys

that he made to the North Pole...

In an aircraft... he came across

an environment down below
that was plush and green

with animals, almost like a sort
of Garden of Eden, if you like.

In other words, what was
seen, perhaps, by Admiral Byrd

at the North Pole was
actually an entrance

into a parallel world,

a parallel existence

that exists and coexists
with the Earth itself.

Is it possible that Admiral Byrd

saw an entrance to Inner
Earth at the North Pole?

Almost a century after
his alleged discovery,

there's no way to know for sure.

But modern science
is trying to solve

this centuries-old mystery
by conducting seismic studies

of the interior of the planet.

One of the pieces of data
that was really earthshaking

was when Washington
University published the discovery

of another ocean underneath
the crust of the Atlantic Ocean.

They could actually read
the waves crashing on a shore

on the inside of the crust.

That was really
quite remarkable.

When I see reports like
that, it leads me to believe,

at least, that
there's a possibility

that we have a Hollow Earth.

If we gather evidence to prove

that our planet
is actually hollow,

it could change everything.

Maybe the ancients
were right all along.

Does the Earth really have
enormous hollow expanses

beneath its surface?

It's a wild thought to consider,
but one way or another,

we may soon find out the answer.

Because according to some,
the future of humanity lies

not on the surface of the planet

but rather deep underground.

On the surface, this remote town

which is located in a
harsh sandstone desert,

looks like a normal
rural community.

But appearances
can be deceiving,

because as it turns out,

most of the town is
located underground.

Beneath the surface
of Coober Pedy

lies a subterranean world,

complete with homes
that are known as "dugouts"

and other living necessities.

Coober Pedy is-is an incredible
town in the Australian Outback.

You go down these ramps
into an underground space,

and then, you start
seeing restaurants,

hotels,

people's houses,

churches underground.

All of this stuff excavated
from this soft but very firm rock.

What would possess people

to live in such an unusual,
underground community?

Well, the history of
subterranean living

in Coober Pedy
dates back to 1915,

when miners first
traveled to this area

to dig for gold
and precious opals.

The name for Coober
Pedy comes from Aboriginal people

that lived there when the
first explorers came out.

Coober Pedy means
"white man in a hole."

'Cause they saw these people

digging into these things and
disappearing into the Earth.

And of course, were
confounded, like,

"Why do you keep going in there?

What do you want in this place?"

Today,
Coober Pedy is more famous

for being an alternative
lifestyle community

than it is for opal mining.

According to recent estimates,

there are 1,000
individual dugouts carved

into the rock at Coober Pedy,

and approximately 2,500 people

live and work here year-round.

But do residents
of this unorthodox community

enjoy their
subterranean existence?

Well, if you ask the
people of Coober Pedy,

they'll tell you they wouldn't
want to live any other way.

While the story of Coober Pedy

and its residents
is extraordinary,

some people believe
that underground living

is not a matter of
lifestyle preference

but rather, survival.

In recent years, an
increasing number

of so-called "doomsday
bunkers" have been built,

which are designed
to protect residents

in the event of a catastrophe.

One of the most prominent
of these subterranean shelters

is Vivos xPoint,

which is located
in South Dakota.

Vivos xPoint is the largest
survival community on Earth.

It was originally a
government facility

that was in charge of
munitions for World War II.

We have 575 bunkers

spread out across 7,000 acres,

or about nine square miles,

which is about half
the size of Manhattan,

that are now being used for
underground living and survival

in case of the worst possible
events we might encounter.

People who live out there,

they're regular
people like you and I.

And they come from
all different walks of life.

I think it always
pays to be prepared

to survive whatever may come.

If we think about

bunkers that are being
built around the world,

all of these spaces
are connected

by a fundamental belief

that the underground
is a space of protection.

So it completely makes sense,

because humanity has
always sought the underground

to hide from a
hostile environment.

In the future, will
millions of people

actually live a
subterranean existence?

It may seem unlikely,

but the truth is
that humanity's fate

may indeed rely on
what's deep underground.

For instance, there are places
where people have drilled

two and a half miles beneath
the surface of the Earth

in search of a rare
and precious metal

that is critical
to our survival.

Gold.

In this nation located
between South Africa and Mozambique,

stands an ancient,
stepped mountain canyon

known as Bomvu Ridge.

The Bomvu Ridge is significant
because, according to experts,

it is the site of the
oldest mine in history.

Radiocarbon dating,
shows evidence

that this place was mined
40, 50,000 years ago.

And 50,000 years later,

the place is still
producing iron today.

So, the history of
the human species,

from the Stone Age
to the digital age,

has this relationship
to going after the metals

that we need at
that particular place.

It's astonishing to think
that, from the humble beginnings

of the first mine
at Bomvu Ridge,

there are now more
than 6,000 active mines

located all over the world.

Some of today's mines extend
incredibly deep into the Earth,

such as the Mponeng
gold mine in South Africa,

which reaches an astonishing

two and a half
miles underground.

Every year, more than
3.2 billion tons of iron,

gold, silver, platinum
and other precious metals

are extracted from our planet.

Today, we rely on
mining perhaps even more

than our ancestors did,

because modern electronics
depend on what are referred to

as rare earth elements.

The term "rare earths"

refers to 17 chemically
similar elements

that have fantastic magnetic
and conductive properties.

They are called
things like europium,

lanthanum, praseodymium, cerium,

and together they are
absolutely essential

for life as we know it today.

We need these elements
for medical technologies,

communications,
computer hardware.

But eventually,
rare earth elements

are going to peter out.

And the real question is,

how deep will we
go into the Earth

to get the elements
that we need?

I think the simple
answer to that is we will go

as far as our
technologies allow us to go.

Will the Earth's supply
of rare metals eventually run out?

It appears the
only way to find out

is to keep digging
into our planet,

in search of both
essential resources

and also answers

to the many mysteries
that lie beneath our feet.

As humans, we share

this curiosity,

this desire to understand
what's beneath our feet.

And we want to explore.

We want to follow
the breadcrumbs

of this mystery of
what is down there.

Geophysical research

is revealing cave
systems, caverns,

and obviously, whole cities

that were never
known about in the past.

And we are going to discover

incredible things beneath
the Earth in the future

that we could not even
have imagined existing before.

There is something that compels
humanity to explore underground,

whether we're looking
for precious metals

or building new living spaces

or simply satisfying our desire
to descend into the unknown.

And just like our
ancestors before us,

we'll keep digging in search
of all the subterranean secrets

held by our planet
that, for now, remain...

unexplained.

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