This imaginative sculpture is a memorial to this town's former mining industry.

A huge musical instrument played by the ocean.

This abandoned lighthouse looks like a rusting oil rig, but has managed to survive a number of storms.

A visionary Italian architect created an impressive cluster of concrete structures for a family's private tomb.

An intriguing three-sided folly is a testament to one man's devotion to Catholicism and the number three.

Manchester salvaged this sculpture of the adopted Mancunian when it was no longer wanted in Ukraine.

An enigmatic natural rock formation with a manmade passage cut through the center.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

The first mosque in Ghana is known as the "Mecca of West Africa."

The legendary birthplace of the Japanese maneki-neko is dotted with hundreds of lucky beckoning cats.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Abandoned Soviet base once stocked with short and medium range missiles pointed at western Europe.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

Spend your honeymoon where the Devil had his wedding.

The Guardian of Tallinn.

The mummified relic of St. Catherine sits forever on a golden throne.

A massive cave complex boasts some of the clearest water (and most charming bats) in the world.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

This crumbling folly looks like an enchanted left over from Middle Earth.

This lovely little burbling creek is actually a deadly waterway that has dragged down everyone who ever set foot in it.

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

An ancient monastery, a locked room, and a mysterious book heist.