A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

This cafe offers a curated collection of treats and tipples made by monks and nuns.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

A stately palace has been converted into the world's largest cannabis museum.

A beautiful but toxic fountain of mercury.

This semi-secret storybook hedge maze is also the oldest garden in the city.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

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

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

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

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

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

What looks like a suicide in progress is actually a statue of Sigmund Freud.

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

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

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

An ancient city exhumed from the depths of the ocean.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.