This strange geological landscape erupts with sudden bursts of water.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

A city built from mud and known as the "Manhattan of the desert."

A saintly relic hidden in a Prague church basement.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an 8th-century Buddhist master.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

This small primate research island is teeming with playing, fighting wild monkeys.

Enchanting cave with a river crashing through the roof.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

An ancient stone fortress considered by many to be the eighth wonder of the world.

An ancient Egyptian temple in the middle of Madrid, Spain.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

An explosion of natural color known as "the river that ran away from paradise."

Fire meets ice at the southernmost volcano on Earth.

This picturesque mansion has gone from opulent ruin to nature museum.

A dangling church built over a Colombian gorge.

Once the home of a hermetic monk, this cave now houses a small church.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Sloth rehabilitation center in the jungle of Costa Rica.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.

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

Stay in a room with a view... of the bottom of the ocean.