This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A forgotten graveyard lost in the tangles of an overgrown garden.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A 19th-century artistocrat's mansion, turned into a library, hidden in a modern library.

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

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

An artist's cute bronze subway sculptures belie his violent artistic past.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

A collection of comics, graphic novels, animation and caricatures devoted to exploring this often overlooked art form.

Catacombs turned marketplace.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.