Countless grotesque faces stare out from this eerie Prague art wall.

A self-built castle made by a mysterious man.

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

Cat art as far as the eye can see.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Northern Ireland's Brobdingnagian stepping stones.

Ruins of a German Castle on top of a towering stone pillar.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

A Jenga-style cylindrical tower of books that appears to go on forever.

A technicolor place of worship for Elevationists.

One part local history, 99 parts gruesome haunted house.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

Once the most densely populated place in the world, this island is now a ghost town.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

This modern antique shop is a museum for 1980's Saturday morning cartoon culture.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

One of only two commuter aerial tramways in the United States.

Architectureal fantasy quarter of Rome.

Where beautiful signs live on forever.

An underwater city for the dead.