This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

The naturally mummified body of a peasant girl saint.

Thousands of migrating monarchs overwinter clustered amongst the eucalyptus trees.

The oldest attraction in Disneyland is a prehistoric stump that Walt may have bought for his wife.

This eagle-topped spire remembers the military commander who snatched up California for the United States.

The first safe in this California town had to hold all the gold.

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

Flashy signs from Las Vegas’s past find their final resting place at this unusual graveyard.

A glamorous hotel that once accommodated French resistance fighters and concentration camp survivors.

This beautiful Brooklyn monument over a crypt memorializes a grim and largely unknown story from the American Revolution.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

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

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

World's largest collection of serial killer artwork and other macabre exhibits.

World War II-era Nazi compound nestled in the Santa Monica hills.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

A tunnel of hardened lava along Maui’s famous Road to Hana.

Resting place of Hollywood's immortals is also site of summer film screenings.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

The haunting ruins of Jack London's dream house.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

A priest with no formal artistic training used basic house paint to create gorgeous religious scenes inside this historic church.