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

A massive, abstract lookout tower providing a panoramic view of Prague.

What looks like a crashed Zeppelin is actually a bright, airy reading room perched atop a modern museum.

An old asylum graveyard that's been abandoned for half a century attracts those seeking a dark thrill.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

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

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

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

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

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

Macabre astrological automaton clock dating to the late 1400s.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Qatar's oldest market can trace its origins back more than a century.

The World's First 24 Hour Coin-Operated Art Gallery!! Plastic, Styrofoam, and Elvis--If you can't get rid of it, you might as well worship it!!

Forever immortalized in concrete, this Simpsons etching was crafted by show creator Matt Groening.

Beyond being incredibly fun, not much can be said about the Hole with certitude.