All language subtitles for What.on.Earth.S07E06.1080p.DSCP.WEB-DL.AAC2.0.H.264-BTN_track3_[eng]

Narrator:
They're watching you.

More than 4,000 satellites
Circle the earth.

Every day, they uncover
New, mysterious phenomena

That defy explanation.

Discovered from the skies,

A tale of untold riches
And unspeakable terror

In the amazon.

It's monumental!

What were they doing
In the middle of the jungle?

Narrator:
The hunt from space

For putin's
New nuclear mega weapon.

This could attack any major
American city anywhere.

Narrator: and the giant,
Vanishing undersea blob.

Maybe this thing,
This dark mass,

Is alive.

Narrator: baffling phenomena,
Mysteries from space.

What on earth are they?

**

-- captions by vitac --
Www.Vitac.Com

Captions paid for by
Discovery communications

September 3, 2018.

A survey plane flying over
French guiana in south america

Fires a laser pulse
At the dense rainforest below.

Producing a lidar image

Of one of the world's
Most inhospitable jungles.

**

What the lidar has revealed
Is a complex pattern

That sits
Under the jungle canopy.

This is an
Absolutely gorgeous image.

A group of massive
Rectilinear structures.

Clearly, human-made.

There are what appear
To be some type of grid lines.

How old is this?
Is it ancient?

**

Narrator:
Archaeologist mark horton
Has spent decades studying

And searching
For ancient settlements.

He's traveling deep
Into french guiana

To investigate the site
In the aerial image.

Horton: the image
Is really intriguing.

It's such a difficult
And inhospitable place.

But inside this forest,

Major evidence
Of past human activity.

**

Narrator: the pattern
In the lidar image is big.

Analysts estimate it stretches
Across 200 acres

Of dense rainforest.

These forests
Are largely unexplored.

Who went to the trouble
To build this

In the middle
Of this jungle forest,

And where did they go?

South america is full of the
Relics of ancient civilizations.

Is it possible that that's
Exactly what we're seeing here?

**

Narrator:
The hidden structures lie deep

In the 20 million acre
Rainforest,

Up the winding oyak river.

**

Horton:
Here we go.

I think I'm going to need
To find a boat.

**

c'est si bon.
très bien.

**

Narrator:
This forest is sparsely
Populated by the descendants

Of various ancient tribes.

Aerial imaging has uncovered
Historic sites elsewhere

Deep in this continent's
Dense rainforests.

**

But a find in this region
Would be unprecedented.

**

If it turns out to be
A pre-colombian site,

It'd be an extraordinarily
Exciting discovery.

**

Narrator: temperatures here
In the rainforest

Reach 85 degrees fahrenheit.

And the canopy locks in humidity
Like a pressure cooker.

**

The jungle is so hot
And oppressive.

**

Unh!

Whoa.

Narrator: using the image
Coordinates to guide him,

Horton finally gets through
The thick vegetation

And approaches the edge
Of the site seen from the sky.

**

Here we are.

We've got
An enormous building here.

One can see
The foundation of it.

Gosh, it must be
About 30 feet

By about 15 feet in size.

It's -- it's --
It's enormous.

Narrator: and it seems
This building was one of many.

There might be 10
Or 15 of them all in here.

What was their purpose?

Narrator:
Whatever the building's purpose,

Horton discovers
They were dwarfed

By a far grander structure.

This is simply amazing.
Just look at it.

Massive stones,
All beautifully cut.

That is a fabulous
Stone floor that survives.

**

So this is really an elaborate,
Monumental architecture.

Narrator:
If these are the remains
Of an ancient people,

They were
Accomplished architects

With significant resources.

Horton: actually, hang on.
These are steps.

What's this down here?

It's a very straight ditch.

So, what can this be?

Narrator:
The archaeologist looks
To the soil for answers.

But what he unearths
Only deepens the mystery.

**

Now, finding this here...

That is a wine bottle.

18th or even
Early 19th century.

This clearly isn't
A pre-colombian structure,

As I thought it might be.

The french are the likely people
That were responsible for this.

**

Narrator:
Military records confirm
That the french colonized

This country
In the late 19th century,

Ushering in an era
Of violence and oppression.

But they settle in towns
Along the coast,

Not disease-ridden jungle
Alive with dangerous animals.

Why would anyone
In their right mind

Want to actually live here?

What were they doing
In the middle of the jungle?

Scanning the image
For further clues,

Horton observes
Similar structures nearby.

Perhaps if I visit that,

I might get some idea
Of what's going on here.

**

Narrator: horton came looking
For an ancient civilization.

Oh, gosh!

Narrator:
He's found something
Quite different.

Horton:
Look at it.

Narrator: a graveyard
Of rusting iron hulks.

Horton:
It's enormous!

Narrator:
The last resting place
Of some titanic engine.

This is one heck
Of a piece of machinery.

**

Narrator:
Whatever took place here,
It was a mighty undertaking.

And at the next clearing,
Horton is stunned

By the sheer scale
Of this jungle enterprise.

Horton:
[ gasps ]

God...
What is this?

Simply amazing.

**

Narrator: coming up, the jungle
Compound's terrible secret.

Horton: this is such
A dark period in our history.

Narrator:
And the sahara's
1,700-mile-long mystery.

The scale of this thing
Is enormous.

**

**

Narrator: mark horton
Is in french guiana

In one of the least-explored
Jungles on earth,

Investigating hidden structures
Discovered by lidar imaging.

**

Horton:
Monumental.

Narrator: he's discovered
Palatial remains

And giant rusting machinery.

Horton:
God...

Narrator: and beyond it,
A brick circle

With more abandoned
Iron objects.

Horton:
What could it possibly be?

Got these cast-iron drums,
Which could be rollers.

Narrator:
The shape of the structure

And the type
Of machinery nearby

Add up to one thing for horton.

Horton:
I think this must be
A very elaborate mill.

**

Narrator:
Searching for signs of what
Could have been milled here,

Horton finds more heavy metal,

A major clue to what drew
The french to this hostile,

Remote area of jungle.

Horton: ah.
This is a great vessel

That would've been used
For boiling sugar syrup.

**

So now I know
What these machines are for.

This must be
A french sugar plantation.

**

Narrator:
Sugar is first cultivated

In french guiana in the 1650s.

Shipping records show that,
By 1750,

It is the most valuable
Commodity in european trade.

Once europeans developed
A sweet tooth,

Sugar became white gold,
In an economic sense,

Narrator:
And 80% of europe's white gold
Comes from south america.

**

So, actually, that explains
The lidar image really well.

These rectangular features are
Clearly feels for growing crops.

**

Narrator:
But there was one problem.

The tropics is heaven
For sugar cane

But hell for humans.

Few would come
To french guiana by choice,

So most workers
Were brought by force.

This is such a dark period
In our history.

Horton:
This must mean slavery

And slavery
On an industrial scale.

**

Narrator:
Slavery records reveal
That between 1502 and 1866,

Of 11.2 million african slaves
Shipped to the new world,

More than 90% are sent
To work in south america.

**

The vast majority
In sugar plantations.

Sugar cane cultivation
Was one of the most brutal

Productive apparatuses
Of the entire colonial venture.

Narrator:
Testimonies of former slaves

Describe 18-hour days
Of backbreaking labor.

A third of new arrivals
Die within three years

While their masters grow rich

And build grand mansions
Overlooking the damned.

Horton: a central square
In the image

Must be the master's house.

The rectangular structures
We saw in the ground

Must be the barrack blocks
To accommodate the slaves.

**

Well, this would be
A central mill here,

Where the cane was crushed.

And the juice would come down
Into refining furnaces.

Narrator:
Accounts of sugar boiling houses

Depict a steaming vision
Of hell,

Where copper cauldrons
Of raw syrup

Bubble at 240 degrees
Fahrenheit.

It would've been
Incredibly hot.

Smoke would've been toxic.

What a hell hole
Down in this mill.

**

Narrator:
Maritime records reveal
That plantation owners,

Chasing yet bigger profits,

Import huge steam-driven
Machines from europe.

It would've been brought over
In large crates on board a ship.

And probably an engineer
Would've had to come out here

Into the jungle
And got it working.

**

Narrator:
The machines represent
Fresh hell for the slaves

Who toil at metal beasts
That can swallow them whole.

If one of the workers
Were to, say,

Get his fingers stuck
In a one of the large rollers,

It would pull in his whole body
And just crush it.

They employed somebody
To stand by with a machete,

To chop the person's arm off

Before their whole body
Could get sucked in.

**

Horton:
It's sickening to think that

All those people were toiling
Just to produce sugar

For people back in europe.

Narrator: in 1817, france bans
The trafficking of slaves.

But records reveal that
Some plantation owners

Ignore the new law.

This then creates, effectively,
An underground market

In which newly arrived slaves

Are not carried
On the official books.

It's the dark chapter
In french colonial history.

Narrator:
Illegal slave trafficking
Allows plantations to continue

Operating in french guiana
For decades.

And the age of the machines
Horton has discovered

Suggests this was one of them.

An illegal operation with
The capacity for 300 slaves.

**

A stain on french history
Hidden by the jungle

For 190 years,
Revealed from the skies.

Bellinger:
These ruins in the jungle
Stand as a monument

To the misdeeds of europeans
Who came to these shores

And decimated the local
Population for their own gain.

**

Narrator:
Coming up, the real skyfall.

This bears striking similarities
To the chernobyl disaster.

Narrator:
And the unlikely key
To artificial intelligence.

Wow, okay.
This is incredible.

**

**

Narrator:
U.S. Intelligence agencies

Operate a fleet of upwards
Of 80 spy birds

To closely monitor
Suspicious activity

In hostile nations
Around the planet.

They want to know
Who's there,

Why they're there,
What they're doing there,

What materials are coming
And going.

And most importantly, what's
The use and purpose of it?

**

Narrator:
In recent years,

Satellites have uncovered
New missile sites in iran

And mass military buildup
In the south china sea.

**

Yet the location of one
Terrifying new russian threat

Has eluded them.

In 2018, russian president
Vladimir putin announced

That russia was
In the middle of developing

A nuclear-powered
Cruise missile.

**

Narrator:
The russians call their missile,

The 9m730 burevestnik.

Western intelligence agents
Call it skyfall.

Skyfall is essentially
The ultimate game-changer.

No defense system is really
Prepared to deal with it.

**

Narrator: unlike america's
Ballistic missiles,

Skyfall is designed
To fly for days

Without refueling and maneuver
To evade interception

As it zeroes in
On its target.

Its propulsion is a small
Nuclear reactor stored on board,

So the missile launches,
The reactor initiates,

And then it can go anywhere in
The world at very low altitude,

Undetectable,
Hugging the terrain.

That would give
The russian federation

This dramatic upper hand

Because almost nothing
Could be done about it.

This weapon could attack

Any major american
Military installation,

Any major american
City anywhere.

**

Narrator:
Analyst jeffrey lewis
Is on the hunt

To find
Putin's new mega weapon.

Turning to planet
Explorer technology,

He forensically compares russian
News footage of a skyfall test

With high-resolution
Satellite images,

A technique called
Geolocating.

Lewis:
They showed us a video
Of them testing it.

And they didn't tell us
Where it was,

But it looked like
It was very far in the north.

**

Narrator:
As he scans the russian arctic,

Some unusual structures
On a cluster of islands

On the barents sea
Catch his eye.

There are a pair of rails
With an environmental shelter,

And we could see that
In the video,

But we can also see it
In the satellite image.

So we were able to take the
Video and match it to this site.

I think this is the site
Where they conducted that test.

Narrator:
But as lewis closely monitors
The missile site,

Something weird happens.

Skyfall disappears.

It's very strange.

We were hoping to spot signs
Of another test,

But we never saw another test.
What we saw

Was they actually packed up
And moved everything out.

Narrator:
The nightmare scenario
Is that skyfall

Is no longer in test phase.

This doomsday weapon
Is now operational.

For lewis, the hunt to find
The missile is back on,

The stakes even higher.

Scanning known areas of military
Activity near the white sea

In the northwest of the country,

A known cold war launch
Facility draws his attention.

Lewis:
This is a place that russia
Used to test cruise missiles,

So I think we should go
Take a look at the place.

Narrator: to lewis, a section
Of the base is suspicious.

It looks exactly like the
One we saw way up in the arctic.

There are a pair of rails with
An environmental shelter on it.

This is a smoking gun.

Narrator:
The satellite images
Reveal the russians

Have moved
Their nuclear-powered missile

To the russian navy's
Primary launch site.

And on august 8, 2019,

Disturbing news emerges
From the skyfall base.

The reports are
Completely confusing.

An explosion has taken place.

[ explosion ]

But we don't even know
What type of explosion this is

Or how powerful it is.

And it leaves basically

The entire international
Community in the dark.

Narrator: under mounting
International pressure

To explain the mystery blast,

Russian officials
Issue a statement.

The russians finally go ahead
And come forward and say,

"Okay, there was an accident
With a missile test,

But, basically,
Don't worry about it."

Narrator:
But over the following days,

The russian story unravels.

Morgan:
In the immediate aftermath
Of the accident,

There are photographs
On social media

That show ambulances,

That show people responding
In hazardous-material suits

And then...

Radiation levels in the area,

Jump up.

That's the cause for
Some serious alarm bells.

Narrator:
It appears that this russian
Nuclear superweapon

Has spectacularly backfired.

Particularly concerning
And telling is,

We have reports indicating

That there's a stockpiling
Of iodine in this area,

Which we know can be used
To mitigate or counteract

The absorption of radiation.

Narrator:
In nearby severodvinsk,
A city of 185,000 people,

Radiation levels jump 1,500%
Above normal.

Eyewitnesses
Report decontamination teams

Arriving at hospitals.

And satellite imagery confirms

A massive radiation
Cleanup operation

Under way at the base.

This ship
Is the serebrianka.

It is a nuclear fuel handler.

It carries radioactive cargoes.

It's extremely worrying
Because it looks like

They've had a major accident.

Narrator:
To cover up the extent
Of the radioactive fallout,

Russia shuts down
Monitoring stations in the area.

The amount of radiation
The skyfall blast released

Into our planet's atmosphere
Remains, for now, a mystery.

What's really alarming
About this

Is that it bears
Some striking similarities

To the chernobyl disaster.

The russians, at first,

Won't acknowledge
That it even happened.

And then,
When they ultimately do,

They downplay the exposure.

Narrator:
What is certain is that
The world has not heard

The last
Of putin's armageddon weapon.

Wawro: is it shocking
That this happened?

Yes.
In the abstract.

But when you consider
It happened in putin's russia,

No, because putin has nothing
But contempt for his own people.

**

Narrator:
Coming up, into the abyss.

One of these opened up
Without warning,

And everything just disappeared
Into the bowels of the earth.

Narrator: and decoding
The giant desert cipher.

This looks like symbols
Or writing.

**

Narrator:
August 25, 2019.

A nearmap survey plane

Scans the coast
Of new south wales, australia.

As it passes over
Redhead point,

It photographs
Something unusual.

Nelson:
Wow. Okay.
This is incredible.

It looks like a bomb that
Went off and created a crater.

Dr. Rice: it looks like
A regular coastline,

And then wham,
Right in the middle,

It looks like a deep hole

Just right there,
Almost perfectly round.

Narrator:
For some, the abyssal image
Is familiar.

The perfect circle shape
Of this structure

And the dark color
Makes me wonder

If what we're looking at here
Is a blue hole.

Narrator:
Blue holes are flooded,
Caves or sinkholes.

Many were formed when sea levels
Dramatically rose

After the last ice age.

Dr. Kays:
Blue holes occur where,
All of a sudden,

There's some sort of collapse.

So you get this hit
Of deep water

That looks very dark blue

Compared to
The surrounding shallow water.

Narrator: blue holes
Are normally found on reefs.

Yet this wouldn't be
The first time a chasm

Has opened up close
To australia's east coast.

In september 2015,

A giant hole appears overnight
At a camp site on inskip point,

Swallowing a 1,000 foot long
Section of coastline,

Cars, and caravans.

People were fleeing
For their lives.

There were campers and tents
That just disappeared

Into the bowels of the earth.

Narrator:
The aerial image fuels fears

That sections of
Australia's east coast

Are collapsing without warning,

A fear made all the more real

By a recent
Scientific expedition

Close to the great barrier reef.

Kourounis:
Researchers have recently
Discovered an area

Where part of the reef
Is actually breaking away

And is perched above
A deep underwater canyon.

Narrator:
The giant disintegrating slab
Is 1 1/2 miles long.

Kourounis:
It's only a matter of time

That this will
Eventually tumble down

And will create a tsunami

That could be
Absolutely catastrophic.

Narrator:
Scientists estimate that
The tsunami unleashed

By the subsea landslide
Will be 40 feet high.

**

Minutes later, it will smash
Into australia's east coast,

Claiming countless lives.

Millions of people
Live along the coast here.

**

If this is a blue hole

And we have sinkholes
Forming on the beach,

That is an immediate indicator

That this is
An unstable geologic area.

It's certainly unsettling.

**

Narrator:
Yet further images
Of the same area

Reveal something bizarre.

Dr. Fanara: wait a second.
It was there,

But then all of a sudden,
It's not there anymore.

Blue holes aren't ghosts.

**

The fact that it's here
And not here,

Maybe this thing,
This dark mass, is alive.

Dr. Kays:
If we started to think about
What could be in the ocean,

That could appear
And then suddenly disappear.

Only one thing comes to mind
And it's not just one organism

But a whole collection of
Animals together in a bait ball.

Narrator:
Bait balls form when schools
Of fish detect threats

In the surrounding waters.

Dr. Kays:
They're all swimming together

And they get more and more
And more concentrated

Because predators like
Sharks and dolphins

And other larger fish

Are surrounding them
And attacking them.

Narrator:
Sometimes formed of hundreds
Of thousands of individuals,

The shimmering fish tornadoes
Confuse attacking predators.

Dr. Rice:
Each fish is individually

Deciding that it needs to band
With other fish.

So this huge cohesive structure
Is actually the product

Of thousands of different
Tiny decisions

Made by these little fish.

Narrator:
Studies suggest each fish
Can detect minute tremors

In the water
From incoming predators.

Ripples of information

Pass almost instantly
From one individual to the next

So that the morphing swarm
Can constantly change shape

To dodge attacks
Yet avoid collisions.

Bait balls actually
Are like a living liquid.

They can separate and flow

While at same time
Come back together.

**

Narrator:
While each fish's brain
Is limited in function,

As a group working together,

They seemingly act
As a more intelligent entity.

Some scientists think
That decoding

How this hive mind works

Is the key to perhaps
Mankind's greatest

Next technological
Leap forward --

Artificial intelligence.

Kourounis: there are robotics
Specialists who are studying

The behavior
Of these bait balls

To help them develop and program
Swarms of interactive robots

All acting as if they're
One almost living organism.

**

Narrator:
Medical researchers
Have also discovered

Swarm like behavior in
Cancer cells attacking the body.

If they can figure out
The bait balls'

Biological algorithms,

They may be able to program
Swarms of nanobots

To destroy tumors,

Transforming medicine
For mankind.

So what we're actually seeing
Here is a beautiful example

Of the way
That small pieces of nature

Can work together
To make something tremendous.

**

Narrator:
Coming up, the sahara's
Mystery mega structure.

This is a monumental task
To have built this thing.

Narrator:
And weird symbols
In the wilds of wales.

There are literally
Hundreds of them,

If not thousands.

**

**

Narrator:
January 11, 2018.

A satellite passing
Over the western sahara

Spots something
In the desert sands.

**

Simpson jr.:
Wow. Pretty weird.

You have a structure
In the middle of the desert.

Chamberlain:
This looks like the outline
Of a building.

But as you look below,

There are things that almost
Look like symbols or writing.

Perhaps this is the remnants

Of some kind
Of ancient settlement.

Horton:
The obvious question is why,

In this incredibly
Hostile environment,

Do we have
Archaeological remains?

Narrator:
Though a barren
Wasteland today, in the past,

The sahara was home to
Many peoples and civilizations.

Climatological studies show
That around 5,000 years ago,

This 3.5 million square mile
Sea of sand

Is a fertile paradise.

In the past,
The climate wasn't as harsh here

As it is today.

Grassland flourished,

Wild animals were able to roam
Freely across this landscape.

Simpson jr.: this is exactly
The kind of place

That people migrating and moving
Would be interested

In stopping and setting up shop.

Narrator:
This region is called
The western sahara

And has been home to the sahrawi
Tribe for countless centuries.

Yet these are nomadic people
And unlikely to be responsible

For the structure
Seen from space.

If they were going
To set up a settlement,

It would be something
That was very temporary --

Put up and taken down.

Narrator:
Studying the image
In more detail,

Hayley chamberlain develops
Another theory.

Chamberlain: these walls
Look like fortifications.

Nearby morocco is known for
Its medieval fortresses,

Called kasbah's.

Narrator:
Kasbah's walls are constructed

From a mixture
Of mud and straw

Yet are highly effective
Defenses.

For medieval rulers,

They are essential
For protecting

Extremely lucrative
Trade routes.

The mud citadel's provide
Haven for camel trains

Containing as many
As 12,000 beasts

Making the two-month-long trek
Across the desert.

Dr. Albertson:
A kasbah would've been
The nerve center of defense

For any particular
Military power in the area.

It also would've been the
Place that kept the people safe.

Narrator:
But carlo munoz spots
A problem with this theory.

Looking closer at the image,
This really doesn't seem like

These are the ruins
Of some abandoned kasbah.

If this were
A medieval-era fortress,

You'd have watchtowers to be
Able to attack your enemy.

Narrator:
Analysts expand
Their search for clues.

South of the mystery structure,
They spot something unusual.

So here we have obviously
A much bigger structure,

Something that looks
Like a built-up wall.

I can actually see it

Kind of cutting
Through the landscape here.

As agrios tracks
The 20-foot-wide structure,

She discovers it's colossal --

1,700 miles long.

That's like a wall stretching
From new york to denver.

Agrios:
This thing just keeps going.

I've gone hundreds of miles
At this point across the sahara.

The scale of this thing
Is enormous.

Munoz: the question is,
Why is there this massive wall

In the middle
Of the sahara desert?

Narrator:
Military records indicate
Both the wall

And the lone desert structure

Lie in a highly disputed
Political hotspot.

In 1976,
The spanish cede the territory

They controlled in north africa
In this region to morocco,

A warren sued for control
Of the area.

The moroccans immediately
Face violent opposition

From the native sahrawi,
Who demand independence.

In response, the moroccan
Government constructs

This giant boundary wall

To cut the sahrawi
Out of their homeland.

In terms of size and scope,
This is very impressive.

This is a monumental task
To have built this thing.

But the u.N.
Does not recognize this border.

In fact, it's still an
International political dispute.

Narrator: the giant wall,
Known as the great berm,

Takes seven years to complete.

The western sahara berm
Really is a marvel,

Both in terms of engineering

And in terms
Of military strategy.

It makes the berlin wall
Look minuscule.

And the only thing in the world
To really rival it

Is the great wall in china.

Narrator:
Investigators think the
Proximity of the lone structure

To the massive wall
Suggests it's connected.

The structure itself is
Certainly defensive in nature.

It could be a support base
Of some sort.

Dr. Albertson: I see things
That are indicative of

Contemporary warfare --
Ditches, elongated walls,

Artillery revetments,
Places that would provide

Support to the type
Of modern military

That's gonna be in the area.

Narrator:
The wall needs supplies to
Restock the 7 million landmines

That line its base,

The longest continuous
Minefield in the world,

And it needs places
To provide shelter

For the 150,000 moroccan
Soldiers that patrol it.

To give you
Some perspective on that,

That's the size of the canadian
And british armies combined.

Munoz:
The facility could be used
For housing equipment,

Heavy weapons to keep operations
Along the berm going.

Narrator: yet this is
A highly hostile region.

And it's impossible
To verify the origin

And purpose of the code-like
Structure seen from space.

**

Coming up, mystery monster
Tracks in the mountains.

Nelson:
These are massive.

It doesn't make any sense.

**

**

Narrator:
April 19, 2011.

The worldview-2 satellite
Flying over wales

Photographs this pattern
Far below.

Nelson:
These are massive etchings
On the side of this landscape

But almost looks
Like little symbols.

There are literally
Hundreds of them,

If not thousands.

It doesn't make any sense.

Narrator:
The haphazard marks crisscross

Over a rural area
Of the country.

Biologist rob nelson
Studies them in detail.

Looks like something
Is scraping away

Or cutting into the vegetation,

But it doesn't seem to bear
The hallmark of livestock

Foraging for food.

Narrator:
Nelson does know
Of one animal

Which can create
Long abrasions in the land.

Nelson:
Maybe this is something
Far more destructive.

Wild boar.

[ boar grunts ]

Narrator: boar were plentiful
In great britain until

They were hunted into extinction
Several centuries ago.

But today,
They're making a comeback.

In the 1970s, some farmers
Were raising them for meat.

They escaped.

And now we have wild boar
In great britain again.

Narrator: male boars
Have corkscrew-shaped genitalia,

Yet sire
Dozens of piglets a year,

Leading to a population
Explosion in the u.K.

Nelson: wild boar have no
Natural predators,

Which means they can roam around
Populating wherever they go.

**

Narrator:
And these horny hogs are on
A collision course with humans.

Hundreds of people report
Terrifying encounters

With beasts weighing
As much as a black bear

And charging
At 30 miles per hour.

Boards aren't something
You want to run into.

They can really slice you open.

They've even been known
To kill people.

[ boars grunting ]

Narrator:
Boar tusks can grow
To over 5 inches long

And are used for both
Fighting and foraging.

Wild boar forage
In straight lines

As they move their head
Back and forth.

So you can imagine
That they could create

These straight lines on
A landscape like we're seeing.

Narrator:
Yet recent boar
Population studies

Suggest this is unlikely.

Faylor:
Records show that,
Though the wild boars

Are spreading
Throughout the uk,

They haven't reached
This part of wales yet.

Narrator:
Other analysts think
The patterns are manmade.

Archaeologists, when
They're evaluating a landscape,

Scrape away the topsoil

To see if there's
Any buried archaeology.

But one possibility is that

These are actually
Archaeological trenches.

Narrator: wales is a hotbed
Of archaeology.

With over 600 castles
Packed into a country

The size of massachusetts

And evidence of human activity
Dating back over 200,000 years.

Wales has a fascinating history.

Bronze age settlements,
Field systems,

Roman villas, medieval castles.

Virtually every field
Has something in it.

And this welsh hillside
Could possibly be

A massive archaeological site.

Narrator:
But for others,
This doesn't stack up.

Dr. Kays:
When you look really close,

You can see these patterns
Are incredibly straight.

They're like what you get
When you mow your lawn,

Only if you were to stop
And then pick up your lawnmower

And then do it again,
And then stop and pick it up,

And go at a different angle.

Narrator:
Yet if these marks have been
Cut out by machine,

They're big and cover
600 acres of moorland.

Gotta be wondering,
Why would they have mowed

These areas
In the middle of nowhere?

Narrator:
Globally, heather moorland
Is incredibly rare.

75% of our planet's reserves
Are found in great britain.

And what little there is
Is in peril.

In the past, these moorlands
Used to have more livestock

Roaming around
Through the heather,

Essentially giving it
A nice trim

And that helps regenerate
The area.

And because the use of livestock
Is decreasing,

You're not getting
New shoots growing.

Narrator:
One possibility is to burn

Back the overgrowth
With controlled fires.

Faylor:
The problem with fire
To cleanse an environment,

Though, is that
With increasingly dry summers,

These fires can go
Out of control.

Narrator:
Analysts learned that,
In response,

Some landowners are testing
A high-tech solution

To the moorland's problems,

One that leaves strip-like
Patterns in the landscape.

**

What has been sent out
Is kind of a robot lawnmower.

It's so crazy.

Narrator:
It's called the flailbot.

Armed with 30 whirring
Steel cutters,

It's a one-ton remote-controlled
Moorland munching monster.

It's pretty much a cross
Between a lawnmower

And a medieval torture device.

Narrator:
By cutting a series of strips
Out of overgrown areas,

The robo mower
Allows the heather to flourish

And creates the bizarre pattern
Seen from space.