All language subtitles for Mysterious.Islands.2024.S01E09.1080p.WEB.h264-EDITH_track3_[eng]

begin hearing strange noises.

Could this be some kind
of sinister continuation

of spy games between
the two countries?

- The goal was to
frighten, demoralize,

and force their enemy
to abandon their post.

[narrator] A bizarre discovery
in a remote Australian island

territory near Antarctica
leaves scientists puzzled.

There's a pile of stones
near the shoreline

that appears entirely
out of place.

Clearly somebody
built this thing here

in the middle of
nowhere, but why?

[narrator] Objects in the waters
off the Dry Tortugas Islands

have links to a dark history.

Just below the waves is
this strange series of dots.

So what are these things?

♪ ♪

[narrator] Isolated, scarce on
resources, islands are worlds

unto themselves.

Bizarre creatures, ancient
gods, and haunting ruins.

Baffling murders
and deadly spirits.

What will be discovered on
Earth's mysterious islands?

♪ ♪

[thunder rumbling]

[narrator] The Republic of Cuba
is the largest Caribbean island

with an area of over
42,000 square miles.

It connects to a chain
of islands called

the Greater Antilles,
which were formed

millions of years ago.

Today, Cuba has a population
of over 11 million

made up of indigenous, African,
and European descendants.

This mixed population is a
result of its colonization

by Spain that began shortly
after their first contact

in 1492 and Spain's
subsequent involvement

in the slave trade.

Cuba claimed its
independence from Spain

and later America
by the early 1900s,

but struggled to find
its path forward

in the decades that followed
until Fidel Castro led a

rebellion to victory in 1959.

Depending on your
point of view,

Castro can be viewed as either
a ruthless communist dictator

or a heralded anti-American
champion of social justice.

He led the country until 2008
when he turned leadership

over to his brother and
ultimately passed in 2016.

Due to the clashing of
capitalist and socialist ideals,

American-Cuban relations
have been strained

since Castro's revolution.

In 1962, tensions peaked
between the two countries

during the Cuban Missile Crisis
as the world was brought to

the brink of Nuclear war.

[narrator] The crisis arose
after American spy planes

discovered Soviet nuclear
missiles on Cuba.

Ultimately, diplomacy prevailed
and conflict between the

two Cold War superpowers
was averted.

President Obama lifted
long-held travel bans

to and from Cuba, engaged
in prisoner swaps,

and finally in 2015, the
two countries restored

diplomatic relations.

However, late in
2016, shortly after

President Trump was sworn
in, something changed.

An employee at the
American Embassy in Havana

reports hearing strange
noises outside their house,

an annoying, near constant,
even mechanical sound

that they can't escape.

[mechanical sounds]

They try closing all
their windows and doors

and even blast their
TV to drown it out,

but nothing works.

And they're not alone either.

Their neighbor, who's
also a co-worker,

is hearing things too.

What's going on?

Perhaps it's something
natural from the environment.

If you've ever been caught
in the midst of a cicada

or cricket mating season,
you know what an audio

assault it can be.

[cicada noises]

Could insects be the
source of the sound?

[Amma Wakefield] Male cicadas
are among the loudest insects

on the planet, transmitting
their sound at 100 decibels

and at a frequency
of 4.3 kilohertz.

And that's just one
male, not even an entire

field of them.

[cicada buzzing]

Cicada calls are so loud,
they can be heard up to

a mile and a half away.

[narrator] Unlike
grasshoppers that rub

their back legs together,

cicadas produce sound
through the vibration

of a pair of drum-like
structures called tymbals

found on their backs
behind their wings.

Cicadas can be found on
every continent in the world,

except Antarctica, with
nearly 1,000 species

throughout the Americas,
including Cuba.

So could they be
making the noise?

[narrator] As the noise
complaints continue,

another staff member
of the embassy reports

that he too is
hearing the sound.

It's noted that the
sound materializes

predominantly at night, not
only in homes, but hotels too.

And all the reports are
within a few miles radius

of the U.S. embassy.

The noise is described
like grinding metal,

a loud ringing, and
even the effect created

when you drive down the
highway with one window open.

Many contradicting descriptions.

And people at the embassy
are reporting headaches,

disorientation, memory
and hearing loss

due to the ongoing
noise pollution.

It's getting serious.

But no matter how many
cicadas or crickets

or some combination
thereof were present,

they would not be able to
cause actual hearing loss

unless one was held
right to your ear

for an extended period of time.

So what else could
be at play here?

Adding a layer of
intrigue to the situation,

the first people to come
forward after hearing the sound

not only work for the embassy,
but are also CIA agents.

Could this be some kind
of sinister continuation

of spy games between
the two countries?

[narrator] Sound has been
used as a weapon,

even by the U.S. themselves.

During the Vietnam War, the
U.S. military employed a

top secret psychological
warfare campaign called

Operation Wandering
Soul throughout Vietnam.

Operation Wandering Soul
played audio recordings

of wailing, sobbing and
screaming in Vietnamese

on the battlefield using
portable speakers.

[various distorted noises]

The goal was to
frighten, demoralize

and force their enemy
to abandon their post.

But results were mixed
and hard to track.

[Sarah Klassen] And eerily close
to the American embassy in

Havana is Guantanamo Bay, the
site of an infamous

American naval base
and detention center,

where there have been many
reports of a practice

known as song torture,
in which pop music

is used against prisoners.

But in both cases, the
subject matter of the audio

was the weapon, whether
played on repeat

or at extreme levels.

However, there is a more
recent piece of technology

that uses audio differently.

[narrator] The weapon is a long
range audio device or LRAD.

When used to communicate,
it offers loud

and clear messaging, but
when employed as a weapon,

it produces an irritating and
potentially painful noise.

[high pitched alarm noise]

The creators of the tech liken
its amplification of sound

to what a magnifying
glass can do with light.

And really anything
over 75 decibels

can be damaging to your hearing.

[high pitched alarm noise]

[Amma Wakefield] But the LRAD
can emit sound at 150 decibels.

That is dangerously loud.

Human exposure to
sound at 150 decibels

causes vibrations that kill
the tiny hairs in our ears

that allow us to hear.

And they don't grow back.

[narrator] LRAD technology was
developed in the U.S. in 2000

to help enforce safe zones
around military vehicles.

When it was used on
civilian protesters in 2020,

many were left
dizzy, disoriented,

and some even reported permanent
hearing loss after exposure.

[high pitched alarm noise]

So the tech had been around
for more than 15 years

when the situation
with the Americans,

now known as the Havana
Syndrome, began.

And the symptoms experienced by
some of the embassy staffers

are similar to the
effects of these weapons.

[narrator] As concerns grow
and the number

of affected staffers rises,
24 employees and diplomats

from the American
embassy in Havana

are evacuated for
testing, some of whom

were mistakenly believed to
show signs of brain injury.

If it were a weapon
like the LRAD,

in order to penetrate
walls and structures,

it would likely be
so loud it would

be impossible to hide from
the greater Havana community.

But there have been no such
reports that we know of.

And these complaints
seem to be coming

from one group, foreign
diplomats and CIA agents.

[Sarah Klassen] Other
experts interpret the sound

as intermodulation disorder.

[traffic noises]

An auditory phenomenon that

can occur when frequencies
from everyday electrical items

are crossed with
surveillance equipment.

But if it were some kind
of accidental distortion,

how is it so widespread?

[narrator] After a
lengthy investigation,

the FBI conclude that no
sonic event could

have resulted in the
physical symptoms reported.

And ultimately, no
actual brain injury

could be attributed to
Havana Syndrome itself.

There is actually another
theory that could apply here.

It might be a functional
neurological disorder

or conversion disorder,
where a person experiences

real physical or
sensory problems

with no underlying neurological
or physical cause.

It's the conversion of emotional
stress into physical reaction.

Moving to a new country
as a foreign diplomat,

it would be stressful
on its own.

But being an American diplomat
or CIA agent assigned

to the Cuban embassy,
it's the perfect cocktail

for a conversion disorder, or
in this case, mass hysteria.

[narrator] Mass hysteria is
identified when

there is a rapid spread
of illness or symptoms

among members of a
connected social group,

but there is no corresponding
organic or physical origin

for those shared experiences.

This could also explain how the
noises and subsequent symptoms

seem to be experienced by
one specific social group,

in this case, foreign diplomats,
CIA agents, and their families.

When reports of the cases in
Havana hit mainstream media,

they had fueled the fire
and whip up tensions

with words like
"victim" and "attack,"

reigniting decades of
unsettled Cold War history

between the two countries.

[narrator] In the end, over 80
embassy staff and their families

report the noise and symptoms.

Even Canadian diplomats
and their families

stationed in Havana
report strange noises

and concussion-like
symptoms as well.

As word of Havana
Syndrome spread

within the intelligence
community and mainstream media,

it seems diplomats all over
the world, from China, Russia,

Taiwan, Colombia,
Germany, and Poland,

all began reporting
similar symptoms.

Ultimately, it affected more
than 1,000 government employees

over several years
across various posts.

Cases of mass hysteria are
particularly interesting

when we look at their
collective symptoms and causes.

They are not fixed over time,
but appear to change with

the culture at the moment.

A mass event was
born from the hysteria

of the Salem witch trials,
when a group of young women

testifying about witches
began screaming and

writhing in court.

It was so compelling, it
led to the conviction

and hanging of 19 women and men.

[narrator] After Germany's use
of mustard gas in World War I,

a form of mass
hysteria was triggered

when groups of people
thought they were

smelling gas in Britain.

And this happened again
in a town in Illinois

after the release of
World War II propaganda

about the enemy
gassing the innocent.

The town became convinced that
they too were being gassed.

Outbreaks of mass
hysteria are prone to areas

where people are forced
together under pressure.

Schools, factories,
military bases,

all are potential hotspots.

Embassies where a large
percentage of employees

are undercover and
former military

would be another prime example.

Given the context of
the time in which

Havana Syndrome appeared, a
world of political mistrust

and massive technological
advancements

and espionage and war, and
let's not forget the impact

of the extraordinary
levels of noise pollution

we live with today, it
makes sense that this

could be another example
of a conversion disorder

like mass hysteria.

[Alison Leonard] But there are
many who are not convinced.

Even though the FBI and
intelligence community

concluded that there
is no evidence

of adversarial weapons at play,
they did not provide an answer

as to what the root cause was.

[Amma Wakefield] Ultimately, in
response to all the chaos and

suspicion, the US ejected 15
Cuban diplomats from Washington

and shut down their
embassy again in 2017.

Trump even returned Cuba to
the State Department's list

of state-sponsored terrorists.

[narrator] To this day, there
are still departments

within the US government
searching for answers

about the sound initially
reported in Havana.

But when it comes
to Havana Syndrome,

what's real and what is not
may be hard to come by.

In January of 2023, the US
embassy fully reopened,

not only continuing
diplomatic relations,

but they began to allow
American travelers

who meet specific
criteria back to Cuba

to enjoy what this
wonderful island

and its people have to offer.

Just over a thousand miles
north of Antarctica,

in the middle of the
South Indian Ocean,

sits Heard Island, one
of the most remote

and foreboding places
on the planet.

Heard is roughly 142
square miles in total area

and is covered by glaciers,
some of which contain ice

that's almost 500 feet thick.

Volcanic activity has
created iron-rich water

around Heard Island,
resulting in high

concentrations of phytoplankton,
the building blocks of

the ocean's food chain.

Because of this,
the island is home

to an abundance of wildlife.

[narrator] In 2016, a team of
scientists is conducting

research in the northwestern
part of Heard Island

near an inlet called
Corinthian Bay

when they come across
a bizarre sight.

There's a pile of stones
near the shoreline

that appears entirely out of
place in this environment.

Looking at it,
there's just no way

that these stones ended
up here naturally.

So someone had to have put
them here in this manner.

What is it?

[Amma Wakefield] It's a
wall that stands almost

five feet tall, though much of
it seems to have fallen over,

likely due to seals.

What is left appears to
be the remains of a house

or structure of some kind.

Perhaps it's a bunker or a
fortification of some kind.

But that doesn't
make much sense.

There's nothing on
the island to defend.

This is not highly
sought-after territory.

[narrator] Continuing to explore
the area, the team makes another

surprising discovery
not far from the

mysterious pile of stones.

There are remnants
of what looks like

an old structure of some kind.

It's falling in on itself
and there's wooden

debris scattered around.

Clearly, somebody
built this thing here

in the middle of nowhere,
but who would have lived

on Heard Island and why?

- The next closest
inhabited places

are the Kerguelen Islands,
nearly 300 miles away,

and Mawson Station, Antarctica,
over 1,000 miles away.

Both host permanent
research bases.

Perhaps Heard Island was a base
for scientific research as well.

[narrator] Expanding the
investigation, the team comes

across another
bewildering sight.

There are rusting cast
iron pots littered around.

This isn't your average cooking
or camping equipment, though.

These are massive cauldrons,
about four feet in diameter,

and weighing around one ton.

Given the extensive rust, you
can assume that these things

have been lying around
for a long time.

They could have something to
do with the whaling industry.

In the late 19th and
early 20th century,

rudimentary settlements
sprung up in remote places

all over this part of the world.

Whales were hunted
using a combination

of large and small boats,
harpooned and then

hauled back to the camps
where their blubber was

cooked and rendered into oil,

a highly sought-after
commodity at the time.

[narrator] Just off the northern
tip of the Antarctic Peninsula

lies Deception Island, part
of the South Shetland chain,

and it's an active volcano.

There are tanks
on Deception Island

that look kind of similar
to the Heard Island pots.

We know that there
was a whaling station

on Deception Island in
the early 20th century,

and these tanks were used
to process whale blubber.

Is that what was happening
on Heard Island too?

But the tanks on
Deception Island

are way bigger than
the pots on Heard.

It has to be something else.

Seals were widely hunted,
not only for their

meat and pelts, but
for their blubber,

which was processed into
oil, used for cooking,

as a lubricant, and lamp fuel.

[narrator] Around 280 miles
northwest of Heard Island

are the Kerguelen Islands,
a French overseas territory

discovered in 1772.

Similar iron pots to
the ones on Heard Island

can be found scattered
about the coastline

of the Kerguelens.

Based on historical records,
we know that there was

sealing activity here
beginning as early

as the late 1700s.

So if those pots
were used for sealing,

perhaps the pots
discovered on Heard Island

were used to process
seal blubber too.

[narrator] Heard Island
was first sighted by

the British sealer Peter
Kemp from aboard

the ship Magnet
in November 1833,

but he never officially
reported the sighting.

So when American
Captain John Heard

spotted the landmass in 1853,
the island was named after him.

Heard's find made newspapers
around the world,

and it wasn't long before
some enterprising sealers

showed up, hoping to
exploit the island's robust

seal population.

The first landing was
made in March of 1855

by another American,
Captain Darwin Rogers.

On that first trip,
he returned to the US

with around 400 barrels
of elephant seal oil.

More ships were then
dispatched to Heard,

and the island's sealing
era began in earnest.

[narrator] For roughly the next
25 years, hardy crews of men

lived and worked in brutal
conditions on Heard Island's

unforgiving shores.

They would have been dropped
off for months at a time,

left to hunt the seals and then
process the blubber into oil.

It must have been
a harsh existence.

They lived in makeshift
shelters dug into the ground

or crude stone huts, like
the pile of rocks first

discovered by the shore.

[James Ellis] By the 1880s, seal
populations around the island

had dwindled significantly,
and the market for

seal oil was collapsing
due to the development

of cheaper alternatives.

So Heard Island was abandoned,
but sealers never constructed

any permanent structures
while they used the island.

So who could have built
the wooden building?

[narrator] Looking for
answers, the team continues

to investigate a strange object
to the rear of the structure.

It looks like a rusted
old tank of some kind

propped up on a wooden platform.

There's a pipe
extending from one end

and an inscription
above the pipe.

The inscription identifies it
as Furfey's Farm Water Cart,

manufactured by J. Furfey &
Sons in Shepparton, Australia.

Over the name, it says,

"Born about 1880, still
going strong 1942."

This means that there was
a presence on Heard Island

after 1942, over 50 years after
the sealers abandoned it.

So who was here?

[narrator] A deep dive into the
archives of Heard Island

turns up a book entitled

"Fourteen Men," written by
William Arthur Scholes

and published in 1949.

The book outlines the
Australian National Antarctic

Research Expedition to
Heard Island in 1947.

Fourteen men established
a research station

and eventually around 35
buildings were erected,

the ruins of which can
still be seen today.

Their research was mostly
in the meteorological field,

but other studies
were also conducted

between 1948 and 1954.

Ultimately, the station
was closed in 1955

when that expedition
established a permanent base

on the Antarctic mainland.

[James Ellis] Today, exploring
Heard Island is a bit like

walking through a time capsule
from the early sealing activity

right through to
the research years.

There's remnants of an engine
room with heavy machinery,

storage units, and
even a church.

All eerily left to decay
on this desolate island

in the middle of nowhere.

[narrator] In recent years,
efforts to clean up Heard Island

have been successful in removing
some of the debris left behind,

but it's a daunting task
requiring time and money.

For now, the remnants
of days gone by

that litter the shores of this
rugged land of fire and ice

provide a vivid snapshot of the
island's fascinating history.

♪ ♪

The Shetland Islands are a
remote, rugged archipelago

in the North Sea,
roughly 130 miles off

the northeast coast
of mainland Scotland.

At the Shetland's most easterly
point are the Out Skerries,

a group of three small
islands and many tiny islets.

The word "Skerry"
means a rock in the sea

or small rocky island.

And it's usually presumed
that the "out" in the name

refers to the island's
remote location.

But "out" is actually the
Old Norse word for "east."

Only two of the Out
Skerries are inhabited

with a total population
between them

of fewer than 80 people.

This is a sleepy, quiet
place without much going on.

With that said, the
scenery is spectacular.

[narrator] A young couple
is out for a scenic stroll

along the coastline
of the Out Skerries

when they notice something
peculiar washed up on the shore.

It's a black tablet measuring
around 12 by 14 inches

with slightly rounded edges.

It kind of looks like
a chopping board

that you'd find in someone's
kitchen, but thicker.

What is this thing?

[narrator] The couple approaches
the mysterious object

and picks it up
for a closer look.

It's surprisingly light,
only about three pounds,

and feels a bit like rubber.

So obviously it's not a
natural stone formation.

The surface is covered
in slimy algae,

meaning that it's probably
been in the water

for quite some time.

Now here's where things
get a little strange.

They turn the tablet over,
and there's an inscription

stamped on the underside
that reads "Tjipetir"?

"Tjipetir"? What the
heck is "Tjipetir"?

Is that a place?

Is that someone's name?

[narrator] S o-called Tjipetir
blocks have been washing up

on the shores of
the United Kingdom

and Northern Europe
for several years.

They've been discovered
on the coastlines

everywhere from Southeastern
Norway to Northwestern Spain.

Thousands of these
things have been found,

and the fact that
they've come ashore

across such a wide area
is a bit perplexing.

If they all came from the
same place, wherever that is,

it stands to reason
that they would end up

in the same place.

But I guess the Atlantic
Ocean has a mind of its own.

[narrator] Searching for
answers, the couple turns

to the place where
many amateur sleuths

do their investigating,
the internet.

A quick search didn't turn up
any information on the blocks,

only that Tjipetir was the name
of a small village in Indonesia.

So why are rubber-like
blocks stamped

with the name of an
Indonesian village

over 7,000 miles away, washing
up on beaches all over Europe?

The obvious answer would be that
that's where they came from.

Stamping the name of a
place or a company name

that made certain products
was pretty common

in the 19th and 20th centuries.

Think of brickmakers,
for example.

They would put their
name on products

that they would send
all over the world,

and it would be a
way of advertising

everywhere they went.

It's pretty ingenious, really.

So we can assume that these
blocks come from Tjipetir,

but that still doesn't
explain what they are

or how they keep ending
up on European shores.

It seems highly unlikely
that they simply floated

halfway around the
world from Indonesia.

There's a photograph
that appears to be

from the early 1900s
showing a young boy

standing next to a
pile of the blocks

on what looks like a
farm or plantation.

And it turns out the
name of the plantation

is the same as the nearby
village, Tjipetir.

They cultivated a tree
called pallacrium gutta,

the sap of which produces
a rubber-like substance

called gutta percha
that was the de facto

precursor to plastic.

[Dan Riskin] The process was
refined over the years.

In the early days,
the trees were felled

to extract the gutta
percha out of them.

But later on, people came up
with more sustainable processes

like squishing the tree's
leaves with boulders.

That way you could get
the gutta percha out,

mold it into blocks, harden
it, and then stamp it with

the facility's name
without killing the tree.

[narrator] Gutta percha emerged
as a popular alternative

to rubber in the middle
of the 19th century

and was used to make everything
from golf balls to shoe soles.

One of the strengths
of gutta percha

is that it's water-resistant,
whereas rubber degrades

when it's submerged for
extended periods of time.

Because of this, gutta
percha was used extensively

to insulate underwater
telegraph cables.

- The first transatlantic
cable was laid in 1857,

spanning roughly 1,800
miles between

Valencia Island, Ireland,
and Harts Content,

Newfoundland, Canada.

The cable weighed
around 2,000 tons,

250 of which was gutta percha.

It's estimated that 200 trees
would have been required

for every mile of cable.

Gutta percha became
somewhat obsolete

by the mid-20th century
with the invention of

polyethylene plastics.

But even to this day, it's
still used for a few products,

things like sealing wax
and filling material

for dental procedures.

The factory in Tjipetir
no longer stamp their name

in this manner on the slabs.

So if that's the case,
then the blocks washing up

on shore must be pretty old.

Where are they coming from?

[narrator] One of the most
popular online theories

surrounding the mystery
of theTjipetir blocks

is that they are emerging
from a shipwreck,

and not just any shipwreck.

[Dan Riskin] Name a shipwreck.

Exactly, the Titanic.

The timeline fits.

That ship sank in 1912,
right around the time that

the Tjipetir factory
was in full swing.

And according to one
explorer who used a robot

to investigate
that ship's holds,

they say they saw objects
quite difficult to identify

that resembled slabs of gum.

But the Titanic
went down 400 miles

off the coast of Newfoundland
after traveling over

2,000 miles from England.

How could gutter percha
blocks from that far away

end up on European shorelines?

It's quite possible
currents, wind,

and what's called
North Atlantic drift

could very well have carried
the blocks across the ocean.

And given how far
apart they were found,

it actually makes more
sense that they traveled

a long distance
because the further a

cluster of objects
floats, the more widely

dispersed they become.

[Sarah Klassen] Considering how
highly scrutinized the wreck is,

surely somebody
would have noticed

that it was spitting out
slabs of gutter percha.

My guess is the
Tjipetir blocks

are probably not coming
from the Titanic,

but there are other
possibilities.

[narrator] On May 31st, 1917,
the Miyazaki Maru,

a Japanese ocean liner sailing
from Yokohama to London,

was sunk by a German
submarine 150 miles west

of the Scilly Islands off
England's southwestern coast.

The Miyazaki Maru was a
pretty substantial ship,

over eight and a half tons
and almost 465 feet long.

She was carrying
passengers and cargo

under the escort of Allied
ships when a U-boat attacked

with torpedoes.

The ship was lost and
eight people perished.

[James Ellis] It's believed that
sometime before the blocks

started washing up
on European shores,

salvage work was being
done on the Miyazaki Maru,

and they may have pulled
them out of the ship's hull.

- But here's the thing, people
reported finding blocks

before the salvage work
is thought to have begun.

One man claimed that
he found a block

more than 30 years ago and
used it as a chopping board

to gut fish on his boat.

- Maybe there's more
than one shipwreck

releasing the blocks
into the water,

or some of them fell off
a ship 100 years ago

and have been floating
around ever since.

Who knows?

The oceans move in
mysterious ways.

[narrator] British authorities
looked into the matter

and support the
theory that at least

some of theTjipetir
blocks probably came from

the Miyazaki Maru.

Maybe in another 100 years,
they'll still be washing ashore

in places like the
Out Skerry Islands.

The Dry Tortugas are a cluster
of seven small islands

that lie around 70 miles
west of Key West, Florida.

They sit at the mouth
of the Gulf of Mexico.

This archipelago was first
documented by Europeans

in 1513 when Ponce
de Leon visited

and noted over 100 sea
turtles on the island,

hence the name Tortugas, which
means turtle in Spanish.

The word dry was added
once they learned

there was no fresh water
to be found there.

These days, there are
no permanent residents

on the island beyond National
Park staff and their families.

However, these seven
rugged sandy rocks

jutting up from the sea have
a long and mysterious history.

[narrator] In 2016, Josh Marano,
a maritime archaeologist,

is making his way from Key
West to the park via seaplane

when, approaching Garden Key,

he notices something
unusual in the water.

Just below the waves is
this strange series of dots.

Now, this area's rocky,
but these dots appear to

be at regular intervals,
all about the same

distance below the surface.

So what are these things?

The Gulf of Mexico is
home to a number of

important coral reefs, and
Florida is actually the

only continental US state
with 350 miles of reef

formation near its shores.

So perhaps there's some
kind of coral growth.

[narrator] The warm waters near
the Florida Keys reefs

provide a flourishing
habitat of biodiversity

for marine life.

Most areas of the Florida Gulf
have been made protected areas,

including the Dry
Tortugas National Park.

The Dry Tortugas are home
to the third largest

barrier reef in the world.

The reefs of the Dry
Tortugas have been growing

for nearly 12,000 years.

They can be more than 50
feet thick in some areas,

and there are more than 50
different species of coral.

Coral is a pretty
good first guess

about what those dots are,
but the pattern of them just

doesn't quite seem right.

[narrator] Marano notices
that the dots appear

to fall into a linear pattern,
forming a shape similar

to that of a capital L.

[Anthony Cantor] The pattern is
clearly manmade,

and they share a similarity
to something close by.

While no one really lives
on the Dry Tortugas today,

Garden Key, the second largest
of the Dry Tortugas islands,

is home to a fort.

[narrator] Fort Jefferson
is a military fortress
from the mid 1800s.

It's a massive
hexagonal structure

that took 30 years to build,
yet was never fully completed.

Even so, set along one of the
world's busiest shipping lanes,

it was a rallying
point for the US Navy

and a great military asset.

It's the largest brick
fort in the entire

Western Hemisphere,
and it's actually

outlined by a moat.

Could the strange linear dot
seen in the waters to the north

be some kind of
extension of the fort?

The wall of the moat mirrors
the hexagonal shape of the fort,

and at high tides,
they're often submerged.

But the dots don't appear
to be made of brick.

They're much darker in color.

That said, there is something
else at Fort Jefferson

that they do resemble.

[Anthea Nardi] On both the south
and north coast of the key,

there are sets of dots
similar to what Marano found

sitting just offshore.

They're very weathered
and have been in the

water a long time,
but what are they?

[narrator] By the late 1800s,
the fort was eventually

abandoned as a military post,
but it was still used as a

coaling station for warships.

These are pylons or pilings.

They're slender columns made
of wood, concrete, or steel

that are driven deep
into the ground.

They can be topped with a
cap, like the dots that we're

seeing from the plane.

Pylons are support
structures used in areas with

poor soil conditions to
support large builds.

In this case, they're
remains of massive wharfs

used to load and unload the
heavy coal from the ships.

Could this mean that
Marano found pylons

that form a large wharf?

The pylons in the water
around Fort Jefferson

are positioned in these
consecutive rows like a grid.

So you can imagine all
of them working together

to reinforce a
great big platform

holding all that weight
of coal for the ships.

But the dots in the water two
miles out from Fort Jefferson

are spaced out in a single line
with a right angle turn in it.

Maybe it's a more simple
dock like you'd find in

a common harbor?

[narrator] Across
the globe in Egypt,

a team of marine archeologists
were investigating a remote

section of the Red Sea
coast at Wadi al-Jarf when

they discovered something
strange in the water.

It too was an L-shaped structure

stretching out into the
water and then turning

sharply to the right.

It was proven to be the
remains of the wharf

of an ancient harbor.

Maybe these dots are
the remains of a dock

or maybe they're navigation
markers like buoys.

But to what?

There isn't even an
island or key here.

[narrator] Spurred on, Marano
assembles a team of explorers

to take to the waters where
the pylons were found.

Given the spacing
of these pylons,

they do appear to be following
the outline of something,

perhaps a foundation for
a building of some kind.

What would have been built all
the way out here and when?

Through a combination
of factors, weather,

water movement, and erosion,

an island can be worn
down or washed away

as water levels rise around it.

Given that Dry Tortugas
and the Florida Keys

are surrounded by
fragile reefs and sand,

they are especially
susceptible to these changes.

[narrator] The Gulf Islands are
primarily composed

of ancient coral limestone.

Over years of
battering by waves,

this porous rock can wear
down, resulting in the

reduction of the land
area and change in shape

of its coastlines.

People think of erosion as
this slow, gradual process,

and that can be true,
but erosion can also

happen really quickly,
like in the case of

hurricanes and tropical storms
that blow through this region.

Those result in flooding,
strong currents,

and not to mention wind.

[narrator] Global warming in the
Gulf is happening much faster

than in many other
regions of the world,

leading to a variety of
negative environmental impacts,

such as rising sea levels.

The sea levels in the Gulf
region are expected to rise

as much as 18 inches
in the next 30 years.

The Dry Tortugas have never been

particularly high
above sea level.

Loggerhead Key, the biggest
of the islands by area,

is also the highest,
and it only sits

10 feet above sea level.

There are actually
four additional keys

that were once part of
this series of islands

and no longer exist due
to rising water levels.

So perhaps the pylons
are an indication

that this too was
once a large key

that could have
supported structures.

[narrator] Taking to the water
once more, a member of the team

discovers a strange,
oddly-shaped rock with

algae clinging to its surface
10 feet under the water.

The shape is a nearly
perfect rectangle.

It's about six feet
long, two feet wide,

and it's lying flat in the
sediments along the seafloor.

This is clearly not a random
hunk of coral, but what is it?

[narrator] The team takes time
to carefully examine the shape

by cutting away the
seaweed and scrubbing away

the algae and sand to
reveal its original form.

It's a large, fallen tombstone,

and after it's cleaned,
there's a visible inscription.

It reads, "John Greer,
November 5th, 1861."

So who was John Greer,
and what was he doing out

here on this strange key?

[narrator] Armed with a name,
the team searches

archives near and far, and
they discover a wealth

of information about Greer
and his connection to

the Dry Tortugas.

Greer was a scaffolder
who had helped to build

Fort Jefferson before his
death, but if this is true,

why did his grave end up just
two miles away on another key?

85% of Garden Key's area
is taken up by the fort,

so it makes sense that
they would have sought out

more land for things
like burials.

The records show that
Greer is one of dozens

of men buried here, most
of whom were military men,

but that still doesn't explain
what the pylons were for.

[narrator] Nautical records and
maps dated from the time of

Fort Jefferson's construction
referred to a much

larger key at this site,
and not just that, but

this mysterious key
which featured some

kind of large structure.

It seems that as the fort grew,

exceeding its footprint
on Garden Key,

it needed more and more space
for additional services,

especially hospitals.

In the late 1800s, with
yellow fever tearing

through the country and
ultimately this fort,

the military took
advantage of nearby keys

to treat, house, and
quarantine anyone infected.

And the L-shape of those pylons
that were first discovered,

according to the records of the
US Marine Hospital Service,

corresponds to the site of a
30-foot by 30-foot foundation

for one of those facilities.

[narrator] But after 150 years
of being battered by storms

and some of the most fierce
hurricanes on the planet,

the foundation is
all that remains.

Given the severity
of the yellow fever

outbreak at the time,
it makes sense that a

cemetery would be found in
the vicinity of a hospital.

However, whether
or not John Greer

was a victim of that disease
is, as of yet, unknown.

Since the days of the
hospital's operation,

repeated storms, hurricanes,
and climate change

have resulted in
water levels rising,

completely submerging this
key for nearly 100 years.

[narrator] 99% of the Dry
Tortugas National Park

is already underwater.

For the remaining 1%,
explorers in the region

will continue to uncover the
many stories and secrets

these historic and beautiful
disappearing keys hold.