Haunting monument to the German Jewish philosopher who died while fleeing fascism.

The Avenue of Mausolea is a series of grand palatial tombs.

One of the largest, oldest, darkest, quietest motel rooms in the world.

A church of bones, decorated with 40,000 human skeletons.

Giant statue of a disembodied head.

The curious underground history of keeping Paris clean.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

This spacecraft-shaped water tower is only a part of the mysterious UFO mania in this Brazilian town.

Roman ruins top white travertine terraces formed by ancient hot springs.

A Turkish ghost town abandoned in a population exchange with Greece.

A deadly ancient portal to the underworld.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

An abandoned horticulture institute gloomily presides over rows of derelict and vine-wrought greenhouses.