The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

A collection of abandoned typographic signs from Berlin and beyond.

Concerts, art, offices, and a café in what used to be Berlin's first crematorium.

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

Floating swimming pool within a moored vessel.

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

A museum dedicated to a Cold War era sausage.

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

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

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

This little museum is making sure that the art and history of the graffiti sticker is not scraped from history.

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

Art and a pun, all in one.

Hamburgers are intensely proud of their tunnel beneath the river.

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

This monolithic slab of art metal crowns a German slag heap.

This massive steel pyramid can be entered by a set of jagged steps that let visitors stand in its heart.

No need to strap in for a "ride" on this walkable roller coaster.

This strange building looks like a medieval fortress crashed into a 1960s Brutalist office block.

The largest mosque in Germany.

Residing along a busy thoroughfare, this sculpture urges passersby to consider the future.

The body of at least one victim of a construction accident was left behind in the collapsed pylon, buried under tons of concrete.

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