A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

A winding path built in secret on the edge of the continent.

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

A psychedelic labyrinth on the San Francisco bay.

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

This lovely tree was a thank you gift from the man known as "Public Enemy No.1."

This historic hotel on Bathhouse Row in Hot Springs National Park has a storied history of gangsters and baseball greats.

Museum dedicated to awful artwork.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

An allegorical statue of a giant pregnant woman representing justice and truth.

Inside this medieval church resides a unique set of murals.

This tiny chapel next to a highway provides weary travelers a place to rest, pray, or maybe even get married.

Natural time capsule containing an alien ecosystem.

The final resting place of New Orleans' most famous voodoo priestess.

This castle resides in a valley known for immense bloodshed during the Middle Ages.

Nature is slowly overtaking this disused cemetery on the outskirts of Brussels.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

The last Viking king of Denmark is buried inside the crypt of this cathedral.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

This former lieutenant governor's home is brimming with curiosities.

Where America's first doomsday cult awaited the end of the world.

A huge musical instrument played by the ocean.

A memorial to the soldiers who died in the bloody battles to control Verdun in World War I.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.