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

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

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

A beautiful maze marks where three countries meet.

The palace of the King of Kings, burned by Alexander the Great.

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

Rainbow-hued local gem in Venice.

England's most notorious suicide spot.

Museum dedicated to the terror regimes of Hungary.

Where Aleister Crowley taught magick in "La Chambre Des Cauchemars," his "Chamber of Nightmares."

Graffiti, cars, and religion combine to create this jungle of scrap in the Nevada desert.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

This massive underground salt mine now holds a sci-fi theme park in its depths.

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

Not one, not two, but three natural bridges remain in this captivating spot post-sinkhole.

A 19th-century shrine covered with prosthetic body parts as votive offerings.

An abandoned meat mecca now serves as an excellent locale for urban exploration.

A playground built by the kids that is a child's wonderland, and a helicopter parent's nightmare.

Obelisks and stone pineapples in the Irish countryside.

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

Where the lovelorn find a home for their sentimental keepsakes.

Quite simply the largest tree in the world (by volume).

A cave's rare beauty held a cavernous secret hidden underground.

You might know it as the Overlook Hotel, but the inside is not going to be familiar.