A lush green oasis in the middle of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

A unique underground car park that has become a popular filming location.

An abandoned jewel of a ballroom on the top floor of Australia’s busiest rail station echoes with the sounds of a bygone era.

A beautiful 1920s tower filled with local hidden gems.

A saintly relic hidden in a Prague church basement.

A Baroque mansion with ties to legendary magicians and alchemists.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

An existential riddle in the world's largest ancient castle.

This automated sculpture of two men peeing will spell out text messages with their micturition.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

This doorless 20th-century elevator doesn't stop or slow down.

This artificial cave looks like something out of a fairytale.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Walk through Czech history in Prague's largest graveyard.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Two stunning 17th-century libraries and a cabinet of curiosities.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The former headquarters of history's oldest megacorporation.