Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

This unique wooden mosque resembling a Chinese pagoda was said to be built without the use of nails.

Cold war icon and onetime "hole" in the iron curtain.

An abandoned swimming pool decays on the outskirts of Berlin.

A traditional U-Bahn station in Berlin gets a string of rather untraditional benches.

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

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

This secret collection of the strange and occult was rediscovered in a forgotten room of an old house.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

An architect transformed this abandoned cement factory into his castle-like workshop.

The remains of an encyclopedic sculpture garden later used as an internment camp.

Geological storytelling.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

An abandoned Indian-inspired mansion.

A display of torture devices used in the Spanish Inquisition and other scourges of medieval Europe.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

18th century anatomical amphitheater of the Royal College of Surgery of Barcelona.

A once-secret library of Freemason history in Catalonia.

This whimsical winery by Antoni Gaudí looks ripped from the pages of a fairytale.

Mine your own precious stones.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A unique collection of gilded age mechanical pianos.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A grotesque collection of wax limbs depicting the symptoms of venereal disease.