Original subtitles

NARRATOR: A mysterious colourful pattern bursts out

from a monochrome landscape.

- What created those stripes? And how?

NARRATOR: An eerie pattern of circles disturbs

an untouched desert.

- It looks like some kind of symbol, but for what?

NARRATOR: A vast array of ancient etchings visible from the skies.

- This is a seriously weird collection of shapes.

NARRATOR: And a serene lake transforms into a vivid

pattern of spots.

- It looks almost extraterrestrial.

NARRATOR: Everywhere we look on our planet,

there's evidence of the past.

In nature. In buildings. In relics.

Each holds a mystery that technology now allows us to see from above.

What new secrets are revealed?

Concealed in landscapes across the planet,

the view from above reveals perplexing patterns.

Hiding secrets of the natural world and forgotten human exploits,

untold stories ready to be uncovered from the skies.

This is Utah.

In the open terrain south of Salt Lake City,

there are vistas that will take your breath away.

It's a parade of stunning landscapes,

showcasing sand-coloured hills and rock formations.

Until this.

- I'm confused. What is causing this?

NARRATOR: This cluster of contoured hills boasts an unexpected

and hypnotic pattern of polychrome stripes.

These strange formations are known as the Rainbow Hills.

With an elevation of over 1500 metres

they're almost as tall as 5 Eiffel towers.

- If we look at the Rainbow Hills in the view directly above them,

the stripes transform into swirly rings.

- I mean, just look at that!

They seem alive, like a giant coral reef.

- Or maybe some kind of fancy fungi?

- It's mesmerizing to look at, but what created those stripes? And how?

- I wanna know why these colours are here.

NARRATOR: A clue might be found less than 1000 km southwest where

the rolling hills of the sunshine state reveal signs of drought.

- The years 2020 to 2022 were some of the driest years in Californian

history, and multiple seasons of wildflower seeds

just sat in the soil, waiting for water.

- That precipitation came in early 2023

when you have record breaking rain soaking, drenching those hillsides.

NARRATOR: And that huge rush of water creates the perfect

conditions for those long-neglected seeds to blossom come springtime.

Exploding into dazzling patterns of colour on the hillsides.

And blooms this size don't go unnoticed.

- They're even mapped by the local news stations so tourists can

find the best spot to witness their technicolour beauty.

These super blooms are so enormous, they can even be seen from space.

- There's no denying that those flowers are absolutely gorgeous.

Could some kind of bloom be happening on Rainbow Hills?

- If we zoom in closer on the view from above,

I don't see any plant life.

- That means the colours are built into the surface. But how?

NARRATOR: If it's not a plant-life super bloom that creates

these swirling colours in rock, what is it?

Another clue can be found in Southeast Asia where

a multi-coloured pattern on trees is formed by another

natural phenomenon.

They are called rainbow eucalyptus.

- They're iridescent trees native to Indonesia, New Guinea,

and the Philippines.

NARRATOR: Extremely fast growing,

rainbow eucalyptus can reach heights of over 60 metres —

almost 5 times the size of the average telephone pole.

Could a clue to the patterns be found in their height?

- They're speedy growth causes the bark to shed in strips,

revealing a bright green layer beneath it.

- What on earth is it that makes that bark become

so kind of ridiculously multicoloured?

Is it something in the environment?

NARRATOR: The key to these patterns is hidden in the air.

- As that layer gets exposed to the air,

it ages over time into different colours.

NARRATOR: A new green strip of rainbow eucalyptus bark

becomes blue, purple, pink, and then orange as it gets older.

- They look like cartoon trees.

- It eventually turns brown, falls off,

and the process starts again by revealing a new bright green layer.

- Because this process happens continually,

there's always strips of different-coloured shades on the

tree, giving the rainbow eucalyptus its 'fantasy storybook' appearance.

- So, is it possible that the Rainbow Hills are actually

caused by a similar process?

- I don't think 'air' on its own could be changing the surface

colour of the hills.

NARRATOR: So what else could it be?

Over eight thousand kilometres away, another exquisite rock

formation at the edge of the ocean might give us a clue.

- On the Alabaster Coast in France are the Cliffs of Etretat.

- These black and white striped cliffs stand 70 metres

above the English Channel and contain three natural arches.

- The staggering beauty of these cliffs has been

reproduced by many photographers and many actual artists,

including that famed impressionist painter Claude Monet in the 1880s.

NARRATOR: What could be causing the astonishing pattern that

inspired the likes of Monet?

- The black and white stripes are made of flint and chalk.

- The chalk is a form of limestone

and the mineral calcite — which originally

formed under the sea by the compression of microscopic plankton.

Between 80 and 100 million years ago,

microscopic aquatic creatures known as coccoliths died there.

Their skeletons piled up on the seafloor

and turned into a white ooze.

- That 'soup' hardened

and compacted over millions of years into a soft white rock.

NARRATOR: That explains the formation of the white stripes.

But what caused the black stripes?

- The black flint in the cliffs was created by a chemical reaction

on the surface of the chalk, and over time, many layers of this

chalk and flint build up to create the striped pattern we see today.

- So, is it possible that the stripes on Rainbow Hills

are caused by a layering of material over millions of years?

NARRATOR: The striped pattern in the rocks look very similar,

but there is one clear difference - the colour.

So could another colourful landform hold the answer?

- Around 7000 km southeast of the Rainbow Hills,

near the city of Cusco, Peru,

there are massive elevations that are just as breathtaking.

NARRATOR: At 5,200 meters,

these majestic Peruvian mountains are over 3000 meters

taller than the Rainbow Hills and have strikingly similar features.

- They flaunt large swaths of colour that appear to be

sliding down vertically from the peaks.

Those vibrant stripes are made of minerals.

NARRATOR: The mineral stripes originated about 65 million

years ago when marine, lake, and river sediments were

transported there by water that once covered the area.

- Its colours are made up of things like calcium carbonate,

iron sulphide and copper oxide.

- But how did all those minerals in the ground then

end up becoming vertical stripes on a mountain?

NARRATOR: Over time, the mineral sediments formed layers

and the movement of the tectonic plates thrust the layers upwards

forming large mountains and rotating the stripes of mineral deposits.

- The local Peruvians call these colourful peaks 'Vinicunca',

but they're also known as 'Rainbow Mountain'.

NARRATOR: Is it possible this ancient geological

phenomenon in Peru is echoed in the Rainbow Hills of Utah?

Could the striped patterns here be created from ancient ocean minerals?

- If you compare the patterns between the Rainbow Hills in Utah

and the Rainbow Mountain in Peru, there is a distinctive difference.

- The mountains in Peru have vertical stripes.

- But remember the aerial view of Utah's Rainbow Hills?

From above, the stripes look like swirly rings.

That's because the stripes on the Rainbow Hills are horizontal.

NARRATOR: So could another powerful natural force be the cause?

- I have an idea and the clue lies over 9500 km

away from the colourful minerals in Rainbow Mountain to something

that's many degrees colder than anything you'll find in Peru: Ice.

- There are icebergs in Iceland that are more than 1000 years old,

and some of them are pretty crazy-looking.

- But my favourite are the striped icebergs in the Jokulsarlon

lagoon, at the edge of the Breidamerkurjokull glacier.

- Pardon?

How can Icelandic icebergs explain what happened on the dusty

hills in Utah?

- The landscape between these two places is a lot more

similar than you might think.

- Those icebergs got their stripes from another one of Iceland's

famous natural wonders.

- Let me guess. They're volcanoes. - Yeah.

A long time ago a volcano near the glacier kept erupting, and each time

it happened, it deposited a thin blanket of black ash on top of it.

NARRATOR: Snow would fall and freeze on the glacier,

creating a layer of white, and that process continued for many

years to build what looks like a layer cake.

- Because of global warming,

icebergs started breaking off the glacier

and rolling into the lagoon below, revealing the black stripes within.

- So the black stripes are volcanic ash,

and every stripe represents an eruption.

That's wild, but how does this relate to the Rainbow Hills in Utah?

NARRATOR: Utah has many volcanoes with the last eruption only

about 700 years ago, with several others in the last 10,000 years.

- So the colourful stripes in Utah are the handiwork

of an ancient volcano?

- What the National Parks Service in Utah say,

is that the Rainbow Hills are from the Jurassic Period.

That's around 140 million years ago.

I mean, that's when dinosaurs were literally roaming the earth.

NARRATOR: And when volcanoes near the Rainbow Hills

were likely active.

- Scientists believe the Rainbow Hills

and their rings are made of mud, sand and volcanic ash.

NARRATOR: Those elements settled in lakes and swamps,

forming a volcanic clay called Bentonite.

Over time, they absorbed water and dried out in layers.

And because clay erodes more easily than other kinds of stone,

the hills are rounded in shape.

Each layer is composed of iron and other minerals.

As the iron was exposed to air, water, and other elements,

it was chemically altered - resulting in a rainbow of colours.

The stripes with the most iron are responsible

for the overwhelming red shades of the Rainbow Hills.

They are an iconic feature of Utah.

- And there's something else about that reddish,

dusty environment that makes the Rainbow Hills so fascinating.

It's said to resemble the landscape on Mars more than anywhere

else on earth.

- In the early 2000's, the Mars Desert Research Station was

built in Rainbow Hills by The Mars Society.

- The station sends out small teams in the Rainbow Hills

landscape to study what life on Mars might be like,

and to train prospective crews on simulated Mars missions.

- So, if you're just looking for vibrant patterns

and stunning desert views, or if you actually want to pretend you are on

Mars for a bit, the clay on Rainbow Hills in Utah is where you wanna be.

- Just take good care of it.

Because like all the natural wonders on planet earth that took

millions of years to form nothing lasts forever.

NARRATOR: From iconic landscapes to hidden secrets,

the view from above reveals strange patterns across our planet.

And some of these magical formations can be

found in the most supernatural places on earth.

Hidden in the scorching sands of the Sahara desert

east of the town of Ain Salah an uncanny pattern of circles appears.

- I mean that's just bizarre. - What is that thing?

I want to know who made this and why?

- It looks like some kind of symbol, but for what?

- Barring all alien theories, this is obviously human made.

- Who put it here? How long has it been here?

Why is something in the middle of the desert with nothing

else around it?

NARRATOR: This bizarre formation is in the middle of nowhere.

So, who or what could have made this pattern of thirteen circles

that feel strangely familiar?

- To me, the 12 surrounding circles look a lot like a clock.

Maybe each of them represents an hour of time?

- It almost looks like one of those modern watch

faces without numbers or hands, apparently.

- Could it be an ancient sundial?

NARRATOR: Perhaps an answer to this mystery can be

found over 7000 kilometres east in Jaipur, India at one

of the largest sundials in the world.

This is the Samrat Yantra, also known as - 'Supreme Instrument.'

- The Samrat Yantra was built by the Hindu king, Sawai Jai Singh II

in the 18th century, and it's a feat of engineering.

NARRATOR: The gnomon is 27 metres tall and was built

pointing to the north pole and parallel to the earth's axis.

The two quadrants on either side are on the same plane as the equator.

As the sun moves west to east, the gnomon casts a shadow that moves at

2 inches per minute and can measure time to an accuracy of two seconds.

- Is it possible the circles in the sand are at least

part of an ancient sundial?

- The pattern in the Sahara Desert looks like a clock face,

but that's not what sundials look like.

- Plus this is literally the least convenient possible

way to tell the time.

Instead of just looking at a sundial wherever you are, you have to

walk to the middle of nowhere, look at the time, and then go back home.

NARRATOR: If it's not for time measurement,

what could this enigmatic pattern be?

- Since the pattern is in such an isolated location,

maybe it's a sacred place?

NARRATOR: A clue might be found less than 150 km

southeast of the city of Djanet, Algeria.

In the vast Saharan sands,

the view from above reveals other mysterious circular formations.

Archaeologists believe they are structures to venerate the dead.

- There are burial sites known as the keyhole tombs,

named because of their similar shape to a keyhole.

NARRATOR: Made entirely with stones,

some tombs are as long as 300 metres.

They have a rock mound in the centre, and lines of stones

that create a chamber leading to an exterior circle.

- Experts believe they were built by an unknown culture that

dates as far back as 6000 BCE.

Is it possible there is

a relationship between the keyhole tombs and the circles in the sand?

Could it be a group of ancient Algerian burial mounds?

- I'm not convinced the circles are burial sites.

If we look closer in the view from above,

there's no evidence of large rocks or any kind of mounds.

These circles are just flat.

- To me, the pattern we're considering doesn't seem

ancient, it feels like something more recent.

- To me, it looks like maybe some means of visual communication,

but if it is, who's it for?

For planes?

NARRATOR: We might find an answer 11,000 kilometres

west at the Edwards Airforce base in Kern County, California where

a giant shape sends signals to the skies.

This is the Edwards Compass Rose.

- It's the largest known compass symbol on earth,

with a massive diameter of about 1200 metres.

It's used by aircraft to test navigational equipment.

- I know compasses can have a variety of markers on them

besides north, south, east, and west,

but I've never seen 12 like the pattern we're looking at.

- And they're almost always near airports

but the closest airport is almost 200 km away.

- I guess that kills my next theory of an airplane drop zone for

parachuters, because this would be an awesome place to parachute into.

- So long as you have a lot of water to drink

and are willing to take a very long walk through the desert

to find the nearest sign of civilization.

- Good luck with that!

- Okay, so what if we go up higher than airplanes?

Maybe this weird pattern is a type of calibration tool for satellites?

NARRATOR: Satellite calibration compares

objects on the ground with stored data to make sure

the satellite's sensors are capturing accurate information.

- And a great place to calibrate optical satellite sensors

is in deserts because they have consistent atmospheric conditions

and honestly, there's just not a lot of people getting in the way.

- A good example is over 10,000 kilometres

away in Fort Huachuca, Arizona where you can find a weird

collection of lines known as Tri-Bar Satellite Calibration Targets.

- And experts believe that the weird pattern of squiggly

lines in China's Gobi Desert is there for spy satellites.

It looks like art, but it's really undercover engineering!

- Satellite cross-calibration sites come in all shapes and sizes.

- So, this simple desert pattern could be meant to calibrate

satellites.

NARRATOR: But a wider view from above offers another startling clue.

- There isn't just one pattern of circles in the sand,

there are over twenty in a perfectly straight line across the Sahara.

- It almost looks like the pattern has been skidded over the landscape.

NARRATOR: They're spaced about 420 metres apart,

with only the desert sands between them.

- What are they?

- To get at the answer,

we should think about what we can find in a desert, and what we can't.

Deserts lack water,

so humans have to come up with some ingenious way of collecting it.

NARRATOR: The nearest town,

Ain Salah, could not exist without a source of water.

- It's part of an oasis region in Algeria, and the only

way to build an oasis in a desert is with a well-designed water system.

- Are the patterns in the Algerian desert a system to transport water?

Could that be what we're looking at?

NARRATOR: A possible clue is over 5000 kilometres away in Iran

where another strange line of circles creeps across the desert.

These holes make up part of what are known as 'Qanats'.

- Qanats or 'channels' for water were built over 2500 years ago.

- They allow water to travel over long distances

without evaporating and they start by building a series of holes.

NARRATOR: The construction of a qanat begins by digging

a well at the top of a slope.

Multiple shafts are dug to create air flow.

Those shafts are what form the line of holes across the sand.

- A long underground channel is dug to link the shafts together

and force the water to move down.

This can provide reliable water to crops

and livestock in nearby desert communities.

- In Algeria, these water systems are called foggaras.

- They stretch from Southern Algeria to Tunisia and Libya.

Could what we're looking at be a foggara?

- But the holes for foggaras don't look anything like

the circle patterns.

- This is truly mystifying.

NARRATOR: To uncover the truth researchers brave the desert

sands to take a closer look at these mystifying patterns.

These are the circles in the sand.

- The circles are actually very faint.

They're just a subtle change in the quality of the sand.

NARRATOR: And what was found with them is just as perplexing,

thin wires.

- If we look at the wires, they go into the ground,

which likely means there are explosives down there.

- But why would someone bury sticks of dynamite in a circle

in the middle of the Sahara Desert?

- Oil. Or more specifically, petroleum.

Could these circles be from a seismic survey?

- In seismic surveys, reflected sound waves are used

to produce a 'cat scan' of what exists below the earth's surface.

NARRATOR: In modern times,

a mechanical device creates vibrations, or seismic waves that

are received by geophone sensors at different offsets and locations.

Using mathematics, they can discover deep layering and oil deposits.

- But history tells us that in many countries, dynamite was an early

method of creating the vibration needed for a seismic survey.

NARRATOR: This was the technique used in the Algerian desert.

The dynamite was buried in the sand in specific

locations to create maximum vibration.

- When it exploded, it created the circular pattern we see now.

- Is there a way to figure out who buried this dynamite?

NARRATOR: A clue has been left nearby.

Old tin cans discarded as garbage.

- They were for sardines and tuna -

likely lunch containers from the workers who buried the dynamite.

- The markings on them trace back to the late 1950's.

What oil companies were in Algeria at that time?

- Back then, the Sahara Petroleum Research

and Exploitation Company, also known as CREPS, was working in the

area with the Shell corporation and the French government to find oil.

NARRATOR: CREPS was the first to strike oil in Algeria in 1956,

marking the beginning of the oil industry in the country.

- So, now we know who created these strange circle patterns,

and why they were made.

NARRATOR: These desert circles will likely remain for many

decades to come.

Evidence of an almost seventy-year-old mystery

uncovered from above.

On the western coast of Peru, beyond serene beaches,

lush rainforests, and Andean mountains a hypnotic pattern

appears upon a rocky, barren hillside.

- Well, that's odd.

- It looks like someone scribbled across the hill.

- This is a seriously weird collection of shapes.

Are they forming some sort of pattern?

NARRATOR: The strange sight is near a small town called

Casa Blanca in the majestic Casma Valley.

One of over 50 Peruvian river valleys that

flow into the Pacific Ocean.

- That pattern is almost labyrinth-like.

- It's quite a bizarre arrangement, you know, with the kind

of squared off circles and they rounded squares if you like.

- What are they? Are they intentional? Who did these, and why?

- The surface looks very dry, but there's vegetation not far away.

Could this pattern be related to farming?

NARRATOR: Perhaps a clue can be found

just over 8,000 kilometres away on the Canary Islands of Spain

where another perplexing pattern is etched in the earth.

- La Geria has an incredibly unique volcanic landscape created

by the eruption of the nearby 'Fire Mountains' in the 18th century.

NARRATOR: But what are these crater-like indentations?

- Surprisingly, it's a vineyard.

The black, circular pits known as zoco,

are 1 meter hand-dug holes planted with luscious grapevines.

- The many layers of ash on the ground retain moisture from

small amounts of rainfall, dew, and the trade winds from the Atlantic.

That's enough to give these vines complete nourishment.

NARRATOR: Could crops be behind the circle patterns on the arid

hill near Casa Blanca?

- Maybe food crops can grow in the rocky, barren terrain.

- It's possible. Peru can suffer from severe droughts.

Over a thousand years ago, there was a particularly harsh dry

spell that lasted about a hundred years.

- So, what the local people had to do is get seriously

creative with their farming.

- It's said that circular planting techniques can produce more

food using less space and less water.

- So maybe the patterns at Casa Blanca are related to ancient

agricultural experiments?

- The problem I see here is that the pattern just isn't very consistent.

- Even ancient farming practices had some uniformity,

some logic, in the way crops were planted.

NARRATOR: So, if these strange patterns aren't signs of

farming during drought - could they be related to the opposite problem?

- Along with drought, Peru can suffer punishing rain.

- For centuries, people in the area have struggled to survive

through the weather phenomenon known as El Nino - which can

result in torrential rains and devastating floods every 2 years.

- It happens when the temperature of the eastern Pacific Ocean rises,

and the winds weaken or change direction.

This sends warm surface water eastwards, and means that more heat

is released into the atmosphere, creating wetter, warmer air.

- Coastal regions of Peru can be heavily impacted by relentless

rains, drastic flash floodings, and devastating mudslides.

- And the destruction is so severe that they're believed to be

connected to the collapse of entire ancient cultures.

- As recently as 2023, almost 800,000 people were

affected by the storm, with over 40,000 homes destroyed.

Is it possible the Casa Blanca patterns are related

to extreme rain?

NARRATOR: Could we be staring at ruins?

The ancient aftermath of a devastating El Nino?

Perhaps the answer can be found in other ancient

structures in Peru built to protect from extreme weather.

- The area has been victim to plenty of peril thanks to the El Nino

phenomenon.

- So, is it possible this pattern could be settlement

structures that fell victim to El Nino climate events?

- It's not an outrageous idea.

I mean, could these shapes have actually been buildings?

NARRATOR: All across Peru signs of ancient civilizations stand

out on the landscape.

- The Sacred Peruvian City of Caral-Supe is the oldest

centre of civilization in the Americas at 5,000 years old.

NARRATOR: Its complex architecture features monumental stone

and earthen platforms, circular courts, and large pyramids.

These structures form similar shapes to the Peruvian patterns

and were built in a valley to withstand heavy rains.

Similar ancient settlements like Kuelap

and Machu Picchu were built on hilltops because the height

offered protection from mudslides and floods.

But the patterns at Casa Blanca are on a steep

angle at the base of a hill.

- If there was something built here, it would have absolutely been

vulnerable to destruction from flooding and mudslides.

NARRATOR: So if these patterns are not the footprint of ancient

architecture, what could they be?

Perhaps the answer lies in another part of Peru.

Almost 700 kilometres away from Casa Blanca,

familiar dramatic shapes are etched into the landscape.

These are the Nazca lines.

- There are over 350 geometric figures, around 800 lines,

plus circles, trapezoids, and even spirals.

- And about 70 animal silhouettes

and plant designs known as biomorphs.

- These were scratched on the surface of the ground

more than 2,000 years ago.

NARRATOR: The Nazca lines are what is known as geoglyphs.

- Geoglyphs are large-scale works of land or rock art formed by earth

and stone.

NARRATOR: They are often believed to be for religious purposes -

offerings to the Gods -

and can be found around the world - with hundreds just in Peru.

Could this be what we are seeing on the scrubby

hillside in the Casma Valley?

- These patterns in the Casma Valley feel different to the lines,

motifs, and figures currently documented across Peru.

- What is it that makes those Casa Blanca geoglyphs just so distinct?

NARRATOR: The difference is in the patterns.

The geoglyphs are mostly circular, aligned one behind the other.

- This is special characteristics in this specific place, in this area.

In this case, we have a circle made of stones.

All this surface is covered by rocks,

rocks that are dark colourations.

So, they pick up the rocks and concentrate them

in some places and clean the surroundings.

- The Casa Blanca geoglyphs share a similar construction

technique to the Nazca lines - the 'positive

technique' of the stacking and forming of rows of stones

around the figures, as well as the 'negative technique' which

consists of selective scraping of the desert surface.

- Which culture out of the many who lived here actually created

the geoglyphs?

- Is there anything nearby to explore that could help us

to at least speculate?

NARRATOR: Shards of ancient pottery found by archaeologists give

a clue to whom might be responsible.

- Very close in this area, we have pottery from ancient cultures.

This is a piece of jar of the Casma culture.

And based on this kind of pottery,

we can talk about the antiquity of the geoglyphs in this place.

NARRATOR: The Casma culture lived in the valleys around Casma River

over 1000 years ago

and took great pride in their spiritual planting practices.

- It's possible that these geoglyphs were associated with this

culture, the Casma culture.

- Assuming the pattern was created by the Casma culture over 1000

years ago, can we make a guess as to why they created the geoglyphs?

NARRATOR: The archaeologists have a theory.

The geoglyph may be asking the Gods for rain in the mountains,

so there would be plenty of water in the valley below where

the people lived and farmed.

It's a good guess because of where the geoglyph is located

but it's not the only pattern in Casma Valley.

There's also this.

NARRATOR: What could it mean?

In the hopes of solving this ancient mystery,

the team turn to a high-tech view from above.

NARRATOR: With a thermal drone flying above can

they solve a thousand-year-old mystery?

- The use of thermal drones allow researchers to filter out

the modern, linear features such as roads,

and focus on a complete visualization of the geoglyphs.

NARRATOR: And they're also documenting evidence of these

geoglyphs before they are lost forever.

NARRATOR: Using a thermal drone at night provides

the chance to record the most detailed image possible.

NARRATOR: The recorded views from above may be the only

way to protect these mysteries.

- There's an urgency to discover and document any

and all other geoglyphs that might exist in the valleys.

Especially before rapidly developing modern agriculture

destroys them forever.

- It's pretty incredible what we can discover

when we combine new technologies like drones and thermal imaging.

It's kind of like having a sixth sense in the sky that can

detect things that we just can't see with our own senses at ground level.

How cool is that?

- We hope these new 'views from above' will allow for many

more like them to be discovered, studied, and ultimately understood.

NARRATOR: But for now, many of these newly discovered geoglyphs

will remain elusive messages to the Gods meant to be seen from above.

On the west coast of Canada, near Osoyoos, British Columbia

there exists a strange, otherworldly sight.

- Huh. - It looks almost extra-terrestrial.

What is that thing?

- This looks like something a few rounds of penicillin could

clean right up.

- It's kind of a little bit creepy.

I think that's a lake, but with spots?

NARRATOR: Despite its strange appearance,

this is a lake known as 'Spotted Lake'.

A site sacred to the Syilx Okanagan people,

in who's tribal lands it lies.

- That is beyond cool.

- This is so spectacular that I can't believe it's real.

What are these spots and why are they there?

- What in the world has created that weird,

organic-shaped polka dot pattern?

NARRATOR: A clue might be found about 850 kilometres southeast

in Wyoming and another collection of round, colourful pools.

These are the hot springs in Yellowstone National Park.

- I remember they've all been given very excellent names,

like the morning glory pool, and the sapphire pool.

NARRATOR: Yellowstone houses the world's greatest

concentration of geysers, mud pots, and steam vents formed over time

by hydrothermal systems and scalding magma deep below the surface.

But it's the hot springs that draw the biggest crowds.

- The Grand Prismatic is the largest and the most stupidly beautiful.

It's got bands of orange, yellow,

and green all around these deep blue waters.

And this thing is the third largest hot spring in the world.

It's got a diameter of 113 meters across.

That is bigger than a football field!

- Is it possible that there's a connection between the pools

in Yellowstone and Spotted Lake in British Columbia?

- Could something extremely hot be happening under the spots

in Spotted Lake?

- It's a very good guess.

I mean, British Columbia has a multitude of hot springs

and volcanoes in the province, even some in the Okanagan Valley, but

there are none in that specific area that could be feeding Spotted Lake.

- I'd like to know if this pattern stays as it is, or does it change?

- Visual records show that the lake can have over 300 distinct

multi-coloured pools that are several meters in diameter,

and the configuration of those pools changes every year.

NARRATOR: So if it's not thermal activity, what is it?

- As pretty as it is, the lake just looks weird.

- Since the water colour in Spotted Lake isn't normal,

could the pattern be the result of a lack of nutrients?

NARRATOR: Almost 7000 km away,

there's a river in Columbia that might offer a clue.

- Known as Cano Cristales it suffers from a lack of nutrients,

and the water runs totally clear because of it.

NARRATOR: But why? What is hiding in the Cano Cristales water?

- A rare plant called 'macarenia clavigera' grows in that

nutrient deficient water, and during the rainy season it starts to bloom.

- It creates a rainbow effect -

and that's why the river is also known as the 'Liquid Rainbow.'

- Maybe something similar is happening in Spotted Lake?

I mean, could plant life be causing the strange patterns?

- If we take a closer look at the view

from above Spotted Lake, I don't detect a lot of plant life.

- The lake looks kind of dead. - But it might not be.

What if the strange pattern is the result of too many

micro-organisms in the water?

I mean, we've all seen bodies of water that have been taken

over by blue and green algae blooms - they can look pretty funky.

- It's true that microorganisms can make it

look like the colour of the water has changed at the surface.

But really what it is, is a microbial mat.

That's a whole community of microorganisms all stuck

together by a slime that they secrete. I love it!

- The bacteria can form these flat tangled webs,

or stubby pillars called stromatolites,

and these are among some of the earliest forms of life on earth.

- How is that even possible?

How can something so tiny change the colour of something so large?

NARRATOR: An example can be found on the other

side of the world 200 kilometres southeast of Addis Ababa, Ethiopia,

where a trio of lakes look like shades on an artists' palette.

- Lakes Shalla, Langano and Abijatta were once connected by an

ancient inland sea, and one enormous body of water known as Lake Galla.

- About 10,000 years ago, Lake Galla shrunk back and created these

three lakes that have taken on three different colours.

- The largest - Lake Shala, is deep blue; Lake Langano is the colour

of sand, and the smallest - Lake Abijatta - is bright green in colour.

- Their colour differences are partly

because of the different depths - Lake Shala is the deepest,

but it also contains a large number of microorganisms.

Lake Langano's yellow colour actually comes from sediment

that flows from nearby mountains.

But the green in Lake Abijatta is likely

due to an abundance of phytoplankton on its surface.

- We're talking billions of phytoplankton.

Like you could practically float in the stuff.

Phytoplankton contain chlorophyll.

That reflects green wavelengths which is why it

looks green to the human eye.

- But these spots don't look enough like a microbial matt or

stromatolites to convince me.

Could there be something else in the water that's

responsible for its bizarre appearance?

NARRATOR: A final clue can be found in the history of Spotted Lake

and the people who have lived by its waters for centuries.

- Research into the lakes' history tells us that it has been

used by the Syilx Okanagan people for centuries as a healing lake.

- Well, if it's not microbial life,

there's definitely something in that lake that makes it extraordinary.

- Could it contain something larger than life? Some kind of elixir?

NARRATOR: Are the waters of Spotted Lake hiding an ancient secret?

- What were they using from this weird-looking lake, and why?

- Legends tell of great tribes at war, who would allow the

wounded to bathe their injured limbs in the lake's restorative waters.

- Whatever medicinal offering Spotted Lake has,

it's clearly powerful to them.

Is there any scientific evidence to support it?

NARRATOR: Spotted Lake contains large amounts of magnesium

sulphate, calcium, and other minerals that are helpful

in healing human bodies and building healthy ecosystems.

- The lake, formed by rainwater and groundwater,

is a 'saline endorheic alkali' lake.

- The only way the level of a 'saline endorheic alkali'

lake can rise is through precipitation - rain,

and the only way it can lower is through evaporation.

NARRATOR: A similar lake exists roughly 1000 kilometres

southeast in Northern Utah.

This is the Great Salt Lake.

- Known as 'America's dead sea', The Great Salt Lake is

the largest saltwater lake in the Western Hemisphere.

- The shores can look almost like a build-up of cracked ice or snow

when the salt levels are high.

And depending on the amount of salinity in the water,

it changes between shades of pinks, blues, golds and white.

NARRATOR: But because of rising temperatures,

the lake is evaporating more and more every year

- which creates a kaleidoscope of colour.

- So, is precipitation

and evaporation behind the colourful pattern in Spotted Lake?

- Could all the lumpy circles in Spotted Lake be made of salt?

- The spots are formed by a precipitation of sulphate salt,

mainly in the form of Gypsum and Epsom salts.

NARRATOR: But the lake doesn't always have these strange,

white, and multi-coloured spots.

- Throughout most of the year, Spotted Lake looks

almost like a normal lake, but as the summer sun grows hotter,

the water evaporates, and the lake becomes almost completely white.

- Some of the minerals dry up,

creating these natural walkways around pools that

look like pale polka dots with hues of blue and yellow and green,

and the specific colour depends on the mineral composition

of each pool.

NARRATOR: Those salt walkways allow access to all of the lake's

minerals.

- The Okanagan people have been using the healing

salts from this ancient lake for centuries.

NARRATOR: But there was a time when they lost access to their land

and the lake.

- Records show that during World War I, hired labourers mined as much

as a ton of salt every day, to be used for ammunition and explosives.

NARRATOR: And in 1979, there were plans to transform

Spotted Lake into a huge entertainment complex and spa.

- But in 2001, after 20 years of protest and negotiation,

the Syilx Okanagan people were able to buy back 56 acres of land,

including their sacred Spotted Lake.

Today, Spotted Lake is fenced off for its own protection,

but visitors can still view it from a distance.

Near a sign reminding them that it's culturally

and ecologically a sensitive area.

NARRATOR: But the best way to see the rare beauty

and natural wonder of Spotted Lake is from above.

- This place is so unique, and so sacred,

that if you ever find yourself in southern British Columbia,

take the trip to Osoyoos and get a look at Spotted Lake for yourself.

You won't even believe it.

NARRATOR: Perplexing patterns can be found everywhere - volcanic

clay stripes, circles in the sand, ancient etchings, and a lake

of spots but it takes the view from above to understand their mysteries.

Subtitles by Sky Access Services