The romantic garden was the epicenter of the Hungarian art scene in the 1880s.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

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

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

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

Countless grotesque faces stare out from this eerie Prague art wall.

A Jenga-style cylindrical tower of books that appears to go on forever.

Hidden behind a gate in Greenwich Village is a little farmhouse that once served as the writing studio of a bestselling author.

Town full of spiritualists, some of whom are mediums, is still in full swing after 130 years.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

Nondescript elevator doors open to reveal a stunning, surreal world.

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.