This massive subterranean fissure is known as the "underground Grand Canyon."

An emerald-green grotto just a short trip from Austin.

Part of one of the largest flooded cavities on the planet, and littered with prehistoric animal bones.

Sloth rehabilitation center in the jungle of Costa Rica.

These mammoth-yet-narrow crevasses in the Earth are perfect for taking an otherworldly swim.

A sculpture of a giant hand reaches for the stars in the middle of the Atacama desert.

This red lake 4,000 meters above sea level is home to rare flamingos.

A valley of unique erosion patterns lends to a view like nothing on Earth.

Death road of Bolivia.

Bolivia's needle-like rock formations.

Astronomical observatory above Lake Titicaca.

A swing to dangle you off the very edge.

The Uros people live on floating reed islands in lake Titicaca.

Hub for hallucinogenic Amazon religion.

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

Death rituals and sacrifice inside a Peruvian megalith.

An unexpected desert oasis in South America.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

White llama terraces dazzle in Peru's "other Machu Picchu."

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

Tucked behind the Institute of Neurological Science down a decrepit street resides the largest display of human brains in Latin America.

A mysterious pre-Incan ruin believed to have miraculous healing powers.

A remarkable geological formation resembling a forest made of stone.