This unattributed sculpture in Amsterdam is hiding in plain sight.

Museum preserving torture methods from the past.

The attic of a four-century-old canal house hides a clandestine church.

Cat art as far as the eye can see.

An old department store turned Nazi prison turned artist commune.

1898 German railroad depot museum with working engines, steam train excursions, and hands-on displays.

The beautiful baroque library of the Hapsburg empire.

The Goose Girl of Göttingen, Germany might well be the most kissed girl in the world.

This German museum is devoted to all aspects of grave culture from headstones to coffins.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

This temple to the sturm and drang of Richard Wagner contains a dragon's cave and reptile zoo full of living "dragons."

Handsomely crafted representations of our round planet.

Boats must transform into railroad cars to navigate this Polish canal.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Puppet theater and museum holding a collection of more than 300.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Named after a militant urban guerilla, this famous former squat is a graffiti-covered stronghold of leftist culture.

A fascinating insight into daily life in the Eastern Bloc.

Blitzkrieg bop your way through Berlin's Ramones Museum.

Dolls of all shapes and sizes display the eras of femininity in this spooky and beautiful collection.