Ecosystems

Asia's largest limestone cave is home to a world of plastic goblins and gold mining history.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

A subterranean Holocaust refuge within one of the world's longest cave systems.

This series of Armenian caves held the oldest brain, shoe, and winery in the world.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

A popular swimming hole that hides one of America's most deadly diving spots.

Caves that can't seem to quit producing the remains of prehistoric humans.

This California estate was either haunted by ghosts or the Marx brothers.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

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

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

The name of this ancient Indonesian temple translates as "Elephant Cave" but it could be more accurately called "The Hellmouth."