Forests of the Maya Mexico: Earth's Festival of Life


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Forests of the Maya

Documentary revealing Mexico's astonishing wildlife, landscape and culture. The ancient temples of the Maya tower over the forests of the Yucatan.


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In the heart of the Americas...

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..where continents collide...

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..there's a land full of natural riches...

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BIRDS HONK

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MONKEY GROWLS

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..a land of towering giants...

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..scorching sands...

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..and secret rivers.

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Where great civilisations rose...

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..and fell.

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To succeed here takes passion and spirit.

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This is a country rich in colour and culture...

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..a festival of life.

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This is...

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In Mexico's far south there's a forest full of secrets.

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It's March, the peak of the dry season.

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This pool is fast disappearing...

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..and it draws all the animals from the forest.

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Even the most elusive.

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For a young Morelet crocodile, the pool is also a hunting ground.

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There's plenty of potential prey.

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Trouble is, most are far too big.

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Finally, a realistic target.

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Even at his size, sneaking up in such shallow water isn't easy.

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He needs to change his technique.

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Perhaps an ambush will work.

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Almost.

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Success at last.

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But he's not the only crocodile here.

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And his taste of victory is short-lived.

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There's a reason water is so scarce in this corner of Mexico.

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This great forest, which stretches for almost 50,000 square miles,

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has no major rivers.

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And that's down to the region's unique geology.

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The forest stands upon a vast peninsula, the Yucatan.

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The entire peninsula is a gigantic slab of limestone.

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Limestone is incredibly porous.

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Any surface water swiftly drains away underground.

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And this shapes the lives of all who live here.

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For seven months of the year,

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virtually no rain falls,

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and by April, much of the forest is barren.

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For a mother spider monkey this can be challenging.

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She needs to produce enough milk to feed her baby.

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And that requires plenty of fresh fruit.

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Sometimes, that means travelling over two miles each day.

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But with long, slender fingers and no thumbs to get in the way

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this is child's play for an animal

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designed for life in the tree tops.

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She's taking her youngster to a special place...

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..where she knows there's fruit all year round.

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The ancient city of Calakmul,

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once one of the most powerful in the Maya civilisation.

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In the seventh century, this city was home to 50,000 people.

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The people of Calakmul

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cultivated trees that would fruit throughout the year.

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Centuries later, these ancient gardens have left a lasting legacy.

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There's more fruit here than anywhere else in the forest...

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..even at the height of the dry season.

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Over countless generations,

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the monkeys have passed this knowledge on to their youngsters.

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MONKEY CALLS

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At its peak in the eighth century,

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the Maya civilisation grew to almost 13 million people.

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Theirs was a highly sophisticated culture, advanced in mathematics,

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language and astronomy.

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The huge limestone temples, built to worship their gods,

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are a lasting testament to great feats of engineering.

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Almost every other ancient civilisation in history

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has been built beside a major river.

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So how did the Maya manage without one?

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There are almost 1.5 million direct descendants

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of the ancient Maya living in Mexico today.

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Don Roque and his wife Dona Su live on an isolated farm

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in the heart of the Yucatan's forest.

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GOAT BLEATS

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This farm has been in Don Roque's family for generations.

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With his children grown up and left home,

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nowadays, it's just him and Dona Su.

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They live off the land in a way

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little changed since the times of their ancestors.

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But there's more to their farm than meets the eye...

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..a huge natural well, known in the Yucatan as a cenote.

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A cenote is a collapsed cave.

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Over thousands of years, rainwater has eroded

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the soft limestone on the surface.

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Eventually, the roof weakened and fell.

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This cenote provides Don Roque with water all year round.

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But it's far from unique.

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It's one of several thousand cenotes scattered across the peninsula.

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Cenote comes from the Maya word ts'onot,

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meaning holes with water.

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It was these mysterious pools

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that enabled the Maya civilisation

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to flourish without a major river.

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And the greatest ancient cities were founded beside them.

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Each cenote is an oasis.

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The surrounding forest remains lush,

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even at the height of the dry season.

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Filtered through the limestone, the water is full of minerals.

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It supports a unique community of plants and animals.

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Some fish in the Yucatan cenotes are found nowhere else on Earth.

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Within the dense forest,

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a cenote can remain hidden, even when close by.

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But the Maya had an almost sure-fire way of finding them...

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BIRD CALLS

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..the distinctive call of the turquoise-browed motmot.

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Virtually every cenote has its own colony.

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Elsewhere, motmots prefer to nest alone,

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digging their burrows along river banks.

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MOTMOT CALLS

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Here in the Yucatan, they're forced together,

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sharing limited space on the cenote's soft limestone walls.

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Before a male can start looking for a mate,

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he needs to secure a nest site.

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But this cenote is already crowded.

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17 other pairs are nesting here.

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If he's to fit in, this new arrival must use the right body language.

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MOTMOT CALLS

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A raised turquoise brow is intended to intimidate rivals.

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The pendulous tick-tock of their tails

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has earned motmots the nickname clock birds.

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This male must persevere if he wants to breed this year.

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At last, he's earned his own little ledge of limestone.

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With a gift of food,

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he can get down to the business of attracting a mate.

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There are so many cenotes in the Yucatan

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because of a dramatic event

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that changed the history of life on Earth.

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Around 65 million years ago,

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a huge meteorite collided with what is now the Yucatan's north coast.

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Its effect was so catastrophic...

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..it's believed to have wiped out the dinosaurs.

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In an instant, the impact fractured the limestone platform,

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creating what has become known as the ring of cenotes.

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Satellites have revealed over 200 cluster around its crater.

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Satellite technology is also helping modern-day explorers in the Yucatan.

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And new cenotes are still being discovered today.

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It should be about 50 metres that way. You see anything?

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Sam Meacham and Fred Devos are part of an international community

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of cave divers that has been exploring the Yucatan

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since the 1980s.

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I started out for the thrill of being able to explore something.

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And from a young age, I just was imbued

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with the desire to go out and explore this world.

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Each new cenote adds another piece to the puzzle.

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-Oh, look at this, Sam.

-Wow.

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The moment of discovery, right? You can't beat it.

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In the last 30 years, cave divers in the Yucatan

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have revealed something extraordinary.

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The cenotes are not isolated wells.

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Each is connected by an intricate network of caves and passageways,

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spreading like a spider's web across the peninsula.

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Divers have discovered over 350 caves

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and nearly 1,000 miles of flooded tunnels.

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Including the two longest underwater cave systems on the planet.

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Many of these caverns have seen fewer visitors than the moon.

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The great majority remains uncharted.

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For the ancient Maya, the labyrinth of caves

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was out of reach but not beyond imagination.

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This secret underworld was held sacred.

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Home to the 12 gods of Xibalba,

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it was a place both feared and revered.

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But the ancient Maya recognised their link to this unknown world.

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Trees.

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Always plumbed into the water below,

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trees allow life above ground to flourish.

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No tree is better equipped to do this than the strangler fig.

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Its roots can reach 30 metres into the water below.

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Don Roque uses the fig's roots to enter the underworld...

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..navigating his way down steps carved by his grandfather

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over half a century ago.

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At the bottom of the cenote, Don Roque has a secret garden.

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Here he cultivates a plant that wouldn't survive

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elsewhere on his farm.

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Coffee.

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Above ground it's too hot and dry for coffee to grow.

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Down here it's two degrees cooler and a lot more humid.

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Don Roque's cenote is also a haven for insects.

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Food for a colony of resident cave swallows.

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By May the swallows are intent on one thing.

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Breeding.

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The cenote provides everything they need.

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Down here they have a ready supply of soft mud.

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They use this to craft their nests

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together with fibres plucked from the hanging fig roots.

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All being well, in around a month's time,

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they'll each have a brood of up to five chicks.

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Don Roque's cenote has its own community of life

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thanks to the constant presence of water.

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But the rest of his farm requires something more.

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He plants his land with a mixture of corn, beans and squash

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in a tradition passed down the generations.

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A mix of crops helps maintain the fragile soil

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which lies in a thin layer on top of the limestone.

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But he can't draw enough water from his cenote

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to irrigate an entire field.

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For his crops to grow, Don Roque needs it to rain.

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By late May, change is in the air.

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The Yucatan relies on weather systems

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that develop thousands of miles away.

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Gathering ever more water as they cross the Atlantic,

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they bring the seasonal rains.

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The ancient Maya believed the rain was a gift from the gods.

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For Don Roque, the old gods are very much alive.

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RUMBLE OF THUNDER

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The most important of all is Chaac, the life-giving god of rain.

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It is Chaac who determines each thundercloud.

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CRACK OF LIGHTNING

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RUMBLE OF THUNDER

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Finally letting the rain fall.

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1,200 years ago, something happened that sent the Maya civilisation

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into a dramatic decline.

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Chaac withheld the seasonal rains.

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The Yucatan was gripped by a series of devastating droughts.

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Over 80% of the population vanished.

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One by one, the bustling cities were abandoned

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and reclaimed by the forest.

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MONKEYS HOWLING

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This year the gods have been kind.

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By July, it's raining almost every day.

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MONKEYS GRUNT AND HOWL

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This brings new growth to the forest.

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Good news for the Yucatan's noisiest residents.

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LOUD HOWL

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Howler monkeys.

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Their calls carry for over a mile.

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MONKEYS HOWL

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They howl to let neighbouring groups know their whereabouts.

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This patch of the forest is worth protecting.

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The troop has found a tree with young, succulent leaves -

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a particular favourite.

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But a diet of leaves takes time to digest.

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So howlers spend up to 80% of their time resting...

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..making them amongst the most peaceful of all monkeys

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despite their fearsome calls.

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Baby howlers feed on their mother's milk until almost a year old.

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This is much easier to digest.

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With his mother trying to sleep off her lunch,

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nap time can be a bit dull for a baby.

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RUMBLE OF THUNDER

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All life in the Yucatan benefits from the rain.

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Trees burst into fruit.

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All the new plant growth

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provides food for an explosion of insect life.

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There are over 3,000 different species on the peninsula.

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The insects become food for others.

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Almost all the birds in the forest schedule their nesting to coincide

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with this seasonal bounty.

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The regular rain is also good news for Don Roque.

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In just six weeks his corn has shot up.

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But the explosion of plant-eating insects

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could cause Don Roque problems.

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For his crops to thrive, he needs the help of a natural ally.

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In the heart of the Yucatan,

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there's a cave the locals call El Volcan de los Murcielagos.

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The bat volcano.

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Every day, an hour before dusk,

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it erupts.

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More than three million bats exit the cave.

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The ancient Maya associated bats with death.

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This was a swarm straight from the underworld.

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But bats are vital to life in the Yucatan,

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keeping its insect population in check.

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Each can eat its own body weight in insects every night.

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While the bats are focused on the insects,

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others are watching them.

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Grey hawks...

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..and bat falcons.

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These birds are skilled aerial predators,

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their talons perfectly designed to snatch the bats from the air.

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There are other more surprising hunters here.

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Brown jays.

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They normally eat insects and fruit.

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But the brown jays here have developed a taste for bats.

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The jays don't use talons to catch their prey.

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They use their beaks.

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The loss of ten or so bats barely makes a dent on the swarm.

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Tonight, the colony will consume around 30 tonnes of insects.

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A vital service that keeps the entire forest healthy.

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It's late September...

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..and it has rained almost every day for the last three months.

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Don Roque's corn is now fully ripe.

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In a tradition dating back to the times of their ancient ancestors,

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the first corn of the harvest serves a special purpose.

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Dona Su crushes it to make a sacred drink called atole.

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This is offered to the gods in a ceremony of thanksgiving.

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SPEAKS IN NATIVE LANGUAGE

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From June to November, the Yucatan receives 100 centimetres of rain.

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Across the peninsula, that's over 36 trillion gallons.

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The cenotes are refilled.

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But most of this water seeps through the limestone into the underworld.

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The work of cave divers like Sam is furthering our understanding

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of the Yucatan's unique water system.

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'We're still exploring here.

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'And the more we explore, the more questions we ask.

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'Selfishly, I hope we finish in my lifetime.

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'I don't think we will.'

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Metre by metre, the divers are mapping the underground labyrinth.

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It's a painstaking process with every measurement taken by hand.

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But this has revealed something remarkable.

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The water in the caves isn't just locked within the limestone.

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It flows.

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The Yucatan's missing rivers are underground.

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Like all rivers, they are compelled towards the coast.

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Here, the fresh water meets salt water brought by the incoming tide.

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This border is called the halocline.

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Containing more dissolved particles,

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the salt water is heavier and lies below the fresh water...

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..giving the illusion of a surface.

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But after months of heavy rain...

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..the flow of fresh water prevails.

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At the coast, it leaves the underworld behind.

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Mangroves flourish in the mixture of salt and fresh water.

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The roots provide ideal nurseries for schools of fish.

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And gentle giants are drawn to the Yucatan's shores.

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Manatees come to drink at the outpouring of fresh water.

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As the fresh water flows through the mangroves,

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the trees release tannins, staining it brown.

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Eventually the fresh water reaches its final destination.

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It pours out into the Gulf of Mexico in huge volumes.

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DRAMATIC MUSIC

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Replenished by billions of gallons of fresh water,

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these vast coastal lagoons are the ideal home

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for a colony of the Yucatan's most colourful residents.

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Caribbean flamingos.

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It's been a good year for the colony,

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with nearly 15,000 new additions.

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Finding your chick in such a big crowd isn't easy.

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FLAMINGOS SQUAWK

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But flamingos have incredibly good hearing

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and her youngster has his own unique voice.

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Just six weeks ago,

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the chick was little bigger than his mother's beak.

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These lagoons are full of brine shrimps.

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The beta-carotene in these tiny crustaceans

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gives the flamingos their distinctive colour.

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But it will be another two years before he starts to turn pink.

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Here on the Yucatan's coast, as elsewhere on the peninsula,

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all owe their survival to the secret underworld.

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Without its great hidden rivers,

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this would be a hot, dry and hostile place.

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Born of a unique history,

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the underworld hidden beneath this vast forest

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gave rise to the ancient Maya civilisation...

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..and it remains the lifeblood of the Yucatan.

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Capturing the beauty of the Yucatan's underworld

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meant sending a film crew into one of the most alien environments

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on the planet.

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To do this safely required expertise.

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Between them, this team has over 50 years' experience

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diving on the peninsula.

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I want to make sure we get that right, you know?

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Cameraman Mike Madden was one of the pioneers

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of cave exploration here back in the 1980s.

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And Sam Meacham is part of a team currently mapping

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one of the region's two longest caves.

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There's a common misconception that cave divers are these

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adrenaline junkie risk-takers cheating death on every dive.

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Were tarantulas in our risk management form?

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'When, in fact, we're probably some of the most cautious people

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'on the planet.'

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There's a very real need for caution.

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All diving carries risks.

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But cave diving heightens these risks.

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Surfacing isn't an option if you run out of air.

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This particular cave system, known as Taj Mahal,

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was first explored in 1995.

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It has over three miles of flooded passageways,

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some descending almost 30 metres.

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Filming here poses another challenge.

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Most of the cave is pitch black.

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So the first thing the divers need to do

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is set up a highly specialised underwater lighting rig.

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Four 1,200-watt lights.

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100 metres of cable.

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All of it has to be carried into the cave by hand.

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Lighting the caves on this scale is a new challenge for the team

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and draws on all their expertise.

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Since the 1980s, the dedicated work of divers like Sam and Mike

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has helped put nearly 1,000 miles of the Yucatan's underworld on the map.

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But the vast majority remains uncharted.

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It's pretty amazing that 35 years after the beginning

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of cave diving exploration in this area,

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I would say we're still really beginning to understand

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what's going on here.

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And now there's an added urgency to their work.

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Over the last 50 years the Yucatan's population has skyrocketed.

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The city of Cancun is one of the fastest-growing tourist destinations

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in the world, with over five million visitors every year.

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This creates jobs, but the demand for fresh water

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is putting pressure on the peninsula's underground rivers.

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The future of this area is dependent on tourism

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and so how do we sustainably manage these incredible natural resources

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so that Mexico can continue to receive

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10-12% of its gross domestic product through tourism

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on a 100-mile strip of beach?

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That's important to the future of Mexico,

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not only of this region but the country as a whole.

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Maps of the underground river systems are far from complete.

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New construction work may be taking place above caves

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that are yet to be discovered.

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The entire city of Cancun draws its drinking water from 142 cenotes,

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some of which are now at risk of pollution.

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It's a race against time to reveal the importance

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of the Yucatan's hidden underworld.

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Back at Taj Mahal, with the lights in place,

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the crew are ready to begin filming.

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All our focus is going to be this direction today.

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Every image they film must be meticulously planned.

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Get over. More light.

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Less light.

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Once the dive begins,

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all communication is through hand signals.

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At last the team can capture the splendour of the hidden underworld.

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For most of us, this flooded labyrinth

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remains just as inaccessible as it was to the ancient Maya.

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But for the cave divers devoted to exploring this world,

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the hope is that by opening our eyes to its beauty and importance,

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they will help safeguard its future.

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In the next episode, we head to Mexico's remotest region.

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The far north.

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A land of great deserts and rich prairies.

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Home to the toughest of characters...

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..secret worlds...

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..and some of Mexico's rarest wildlife.

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The ancient temples of the Maya still tower over the forests of the Yucatan, where jaguars, monkeys and vibrant tropical birds now make their home. It is a forest full of secrets, with a vast watery underworld that is still being explored and which holds the key to how animals and people survive the dry season.