These quaint French houses dangle precariously over a precipice.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

When the imprisoned pope's remains were finally returned to the Vatican, his heart stayed behind in France.

These striking ruins of a castle resemble a ship's stern.

A Romanesque tower appears when water levels drop.

Religious dwelling in a Spanish volcano.

Wonderland replication in progress by one persistent man.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Abandoned railway line circling the city of Paris.

Giant heads occasionally litter the industrial Houston neighborhood where sculptor David Adickes has his studio.

One man's homage to the orange as realized through a long-term folk art labor of love.

The world's tallest statue of an American hero.

Crumbling hotel echoes with the sounds of the '30s.

This crumbling UFO is one of only a few remaining "moveable ski chalets" of its kind.

A Texas-sized particle collider that was abandoned due to its Texas-sized budget.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

A store full of vintage and indie toys designed to bring out the kid in even the crustiest of adults.

A grove of colossal man-made flowers built to collect the sun's rays.

Now abandoned, this East Austin school for the disabled began as the "State Colony for the Feeble-minded."

Beer lover's can-covered house.

A decaying concrete oil tanker served as a disposal location for bootleg hootch.

A former electrical substation is now home to an eccentric junk art masterpiece.