An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A former utopian healing center created by a huckster and built by derelicts.

A mountain range on an active U.S. Navy base hides thousands of mysterious prehistoric rock carvings.

This sun-scorched lakebed contains samples of half the natural elements known to humankind.

One of the most unusual geological features, recognizable from a dozen hit movies.

The awe-inspiring ship from the golden era of cruising has an incomparable history and a reputation as one of the world’s most haunted places.

Odd outsider art installations surround a Gold Rush-era ghost town.

The legendary building that needed ghostly approval before being built.

Historic funicular railway, believed to be the shortest railroad in the world.

A natural dome made of volcanic glass in Inyo National Forest.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

One of the oldest living oak trees in the Southeast.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

Thousands of turbines whir at at the origin of North American wind power.

Where a railroad loops under or over itself to rise or drop more than 70 feet in a short distance.

This whimsical seashell-shaped place of worship was designed to blend into its surroundings.

This relic of 19th-century infrastructure is one of the few remaining coal gas storage tanks in the U.S.

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

Toxic waste disaster that founded the Superfund program.