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

This faux-seedy Japanese arcade is made up to look like a maze of alleys straight out of a cyberpunk dystopia.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

This perfectly preserved Chinese medicine shop was untouched for decades before being reopened as a museum.

This lost city belongs to one of the earliest civilizations in the world.

These eclectic homes nestled into the cliffs of a Caribbean island were built entirely from scavenged materials.

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

These blingy, baubled skeletons lie in glass boxes inside a baroque Bavarian church.

The oldest stone house in Paris was built by its most famous alchemist.

The world is full of swimming holes, but few compare to Samoa’s idyllic To Sua ocean trench.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

An unassuming secret door once led to a legendary watering hole.

These crumbling towers are some of the last remnants of a centuries-old Vietnamese culture.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

A giant pineapple, a symbol of hospitality, and an amazing vacation rental option.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

Beautiful public park off the beaten path and away from tourists.

Crumbling remnant of Rio's colonial past tucked behind Corcovado mountain in the neighborhood of Cosme Velho.

This stunning Brazilian library contains the largest collection of Portuguese texts outside of Portugal itself.

A futuristic, brutalist masterpiece that is also strangely prison-like.

The beautiful baroque library of the Hapsburg empire.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

The largest pool at its elevation sits on top of one of the most expensive resorts in the world.