This medieval Italian town is a sheer (and beautiful) cliffside defense.

Local lore claims this park is named after a young woman who jumped off a cliff.

This Queens hospital has stood abandoned for almost 20 years after its patients were secretly relocated in the dead of night.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

This electric green sulphur lake in New Zealand looks like a cartoonish radioactive dump site.

Siberian whale bones stand as cairns marking location of an ancient butcher yard.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

A lake with hundreds of ancient skeletons surrounding it. The surprise is what killed them.

An isolated dive site teeming with cnidarians.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

On Japan's Tashirojima Island, cats are king.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.

Buildings that dynamite couldn't bring down were abandoned because of bathroom issues.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

A toxic ghost town sitting atop a massive coal fire.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

This erect, phallic geological spire wasn't always named so domestically.

A bizarre house filled with an astounding array of collections.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

This giant boulder is pinched over a 1000-meter abyss by two mountains.

Captain America, Sub-Mariner, and the Human Torch were all born in this art deco Manhattan masterpiece.

This evocatively named natural crevasse was created by a torrent of water that smashed right through a granite deposit.

This small group of sand dunes manages to pack in a strange rainbow of colors.

This tiny square mile of Canadian sand was once considered the world's smallest desert.