This concrete residential area doubles as an open-air gallery.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

One of the world's heaviest musical instruments towers within a popular urban park.

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

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

Floating swimming pool within a moored vessel.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

A fascinating insight into daily life in the Eastern Bloc.

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

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A slice of central Asia in the middle of Berlin.

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

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

Abandoned Roman Catholic chapel abused by Satanists before being restored.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

These lesser-known Maltese catacombs date back over 1,700 years.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

A hidden tunnel of bones in one of Malta's oldest churches.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This coffee shop lies hidden beneath a historic church.

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

Black cat statues guard this temple-like Egyptian revival factory.

Classic game cookery takes center stage at what's widely considered London's oldest restaurant.