This freshwater spring fills with 10,000 gallons of water per minute.

Every winter, the wind carves blocks of frozen water into beautiful abstract shapes inside this unusually curved tunnel.

Largest outdoor staircase in the United States.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

This stunning mass of ice spans 121 square miles and is still growing.

This Peruvian bone silo lined with hanging human skeletons and hundreds of skulls is topped with a remarkable Michelangelo replica.

The highest tropical mountain range in the world is in Central Peru, home to a vast array of exotic and quirky plants and animals.

The world's fifth tallest waterfall is a spectacular silver chute of water that cuts through the cloud forest in northern Peru.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

This research hub in the Amazon Rainforest is perched amid one of the world's most biologically diverse landscapes.

Home of the "true" equator.

Ecuador's largest Incan ruins show evidence of sophisticated irrigation and diplomacy among the ancient builders.

A turquoise lake within a volcanic crater.

Massive volcano in the Andes is the farthest point from earth's center.

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

Formerly known as the Malay Quarter, Bo Kaap is a colorfully-painted suburb located in the “Mother City” of South Africa.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Naked scientists race around the pole in the frigid cold to try to join Antarctica's exclusive 300 Club.

Largest sub-glacial lake ever discovered.

These passages carved from the Antarctic ice hold strange shrines to the harsh southernmost climes.

Fire meets ice at the southernmost volcano on Earth.

Southern Ocean waters and glacial forces transform the Antarctic ice into these stunning bridges and caves.

These giant volcano sponges in Antarctica are thought to be the world's oldest living animal, at 15,000 years old.