A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

This modest marker near Notre Dame identifies the very center of Paris.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Notorious artist squat renovated into legal studios.

This massive library holds what was once the largest book collection in the world.

Abandoned railway line circling the city of Paris.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

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

A restaurant and observation deck built in a unique broadcasting antenna.

Berlin's old airport.

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

Started as a kitchen garden, now the second largest botanical garden in the world.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

The largest bottled beer collection in the world holds over 22,000 unique beer bottles.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

A man has revenged his true love's betrayal through tears and stone genitalia.

Sweden's "good old days" painstakingly re-created in a model village.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This Stockholm light tower can be controlled by anyone with a smartphone.