Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

An abandoned swimming pool decays on the outskirts of Berlin.

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

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

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

An eerie, derelict amusement park in Berlin.

Floating swimming pool within a moored vessel.

A wunderkammer of mysterious objects and stories.

Art and a pun, all in one.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

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

A UFO-shaped event building originally intended to be a science museum showcasing the future.

An early 20th-century sanatorium, long abandoned and now being reclaimed by nature.

Abandoned since 1998, this train station has become an oasis for urban explorers.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

Climb inside an iron crystal magnified 165 billion times its normal size.

Lavish royal estate punctuated with heated greenhouses.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Cozy basement bar sports an inventory of over 2,000 beers.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.