♪ ♪ (birds calling) GULNAZ KHAN: The Tayrona people of the Sierra Nevada number around 50,000 and are made up of four Indigenous groups: the Cogi, Wiwa, Kankuamo, and the largest among them, the Arhuaco.

The Arhuaco call themselves the Elder Brothers of Humanity, tasked with an ancient responsibility to guide the rest of the world, their younger brothers, back into balance with nature.

And that really is central in the Arhuaco belief that this is the heart of the world.

It is the beating heart that supplies blood, life to the rest of the planet.

The Mamos are the highest spiritual leaders in the Sierra, and believe they have a cosmic connection with nature.

But they fear that because of humanity's actions, the planet is sick and its heart is failing.

(Mamo Camilo speaks Iku) (conch horn) GULNAZ: The Arhuaco call the Sierra Nevada "the heart of the world" because they believe it's the origin of all life.

They understand the natural world as an interconnected web, and like a living body, every part serves a vital function.

Glaciers feed rivers.

Forests regulate climate.

Coastal wetlands depend on water from the highlands.

When one zone is disrupted, the entire system begins to unravel.

To keep this balance intact, Mamos make pagamentos, ritual offerings that renew the connections among the mountains, sea, and everything in between.

They'll carry the shells they collect here up to the high altitude lakes, physically and symbolically linking the lowland coast to the icy peaks, a reminder that the health of one depends on the other.

And it is the sacred duty of the Mamos to carry out that task.