An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

Most-visited and most-photographed slot canyon in the American Southwest.

An eerie, derelict amusement park in Berlin.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

A bizarre house filled with an astounding array of collections.

An exquisite tunnel of cascading flowers.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

A magical place that lets you play in and explore the world of Studio Ghibli.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

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

A fiery crater has been burning in the Karakum Desert since 1971.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A church of bones, decorated with 40,000 human skeletons.

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

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

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

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The first and only carousel with a lineup entirely of insects.