A sixth-century Byzantine cistern hidden below a modern carpet store.

A marvel of Byzantine engineering under the streets of Istanbul.

A completely underwater art museum sends a stark message about humans' impact on the environment.

Rumors and legends of secret Nazi activities surround this eerily remote island mansion.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

An abandoned canal route lies hidden under the streets of Manchester.

Hidden on the urban banks of a Manchester river are a series of abandoned waterside industrial sites.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

This unique structure allowed boats to bypass underwater mine barriers in the channel to enter the harbor.

This non-profit theatre in the heart of Brussels is dedicated to hosting independent films.

This recently restored crypt was once plagued by liquefying coffins and exploding caskets.

Medical history with an amazing, if frighting, collection of wax diseases on display.

Drink among marionettes at this pub inside a historic puppet theater.

Nature is slowly overtaking this disused cemetery on the outskirts of Brussels.

The Devil’s own choice when he needs a drink in Brussels.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Descend into the tunnels to experience the life of a coal miner.

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

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Zurich's evolution museum hosts a unique collection of skeletons among its natural history treasures.

This building’s ghostly exterior reflects its former lives as a prison, school, and funeral home.

Featuring Zürich's only authentic 14th-century plague doctor's uniform!

A 200-year-old tavern challenges guests to finish a glass of wine while hanging from a ceiling beam.

Museum dedicated to wax representations of disfiguring diseases.