In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A toxic ghost town sitting atop a massive coal fire.

A trash dump made beautiful by nature's power.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

A 140-year-old castle with underground caves hidden in San Francisco.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

A bizarre house filled with an astounding array of collections.

The rocks in this arid basin leave trails of movement behind them.

A snapshot of the city's fascinating voodoo culture.

A psychedelic labyrinth on the San Francisco bay.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

World's first "penitentiary," meant to be humane, drove men insane.

An emerald-green grotto just a short trip from Austin.

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

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The home of pigs, snakes, chameleons, and the alleged largest bunny in the United States.

The flower-shaped temple in Virginia aims to transcend the boundaries of the world’s religions.

An eccentric company offers eccentric millionaires the opportunity to have spaceflight-related experiences.

An alternate history park where the Union Army loses the war... to dinosaurs.