A gateway to a mysterious network of underground tunnels.

Hotel designed by indie graphics artists.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

New fungal and bacterial species call this deadly lake home.

World's largest collection devoted to one fruit.

Walk 2,300 feet above the ground on the "Troll's Tongue."

Once the path of a railway tunnel, now home to thousands of glowing insects.

An optical illusion found amid a logged redwood forest.

The largest of London's subterranean rivers and once a mad, bad center of London life.

Surreal riveted sea forts once protected the Kent shores from German attack.

A Hawaiian stairway to heaven—that you can't climb.

Ride the subways of yesteryear.

Fortified homes of highland warriors that are still in use today.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

This "preacher's pulpit" once used for pagan ritual, is home to a new, and dangerous ritual.

A seemingly endless landscape of pure salt stretches far across Bolivia.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

An odd little fishing town that is inundated by tourists looking to be locked up in a cage and surrounded by great white sharks, because why not?

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

The stoutest tree in the world.

This "floating island" plateau sits 7,671 feet above the forest floor.

A stunning silver lining to global warming's gloomy cloud.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

Hundreds of hidden passageways weave through the old quarters of Lyon.