A line number in Amsterdam that will likely never be used again due to its tragic history.

A poignant museum dedicated to the history of the Dutch resistance against Nazi occupation

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

This cheese shop also houses a museum devoted to Dutch dairy.

The world's only museum devoted to the wonders of fluorescence.

Cat art as far as the eye can see.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

The abandoned remains of this Victorian brewery hide crumbling bowling alleys and rusting industrial gear.

An old department store turned Nazi prison turned artist commune.

A museum dedicated to a Cold War era sausage.

An abandoned swimming pool decays on the outskirts of Berlin.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

Antique frame collection with 2,400 frames.

A museum in the building where Nazi Germany signed its surrender tells the story of World War II from the Soviet perspective.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

Super-heavy Nazi architectural experiment.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

Where once there was a train station bathroom, there is now this German burger joint.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

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

An eerie, derelict amusement park in Berlin.

A surreal museum of extraordinary industrial objects.