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

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

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

A Hungarian pharmacy museum with a box full of mummy powder.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

The first museum in the world devoted to sexual gadgetry.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Two stunning 17th-century libraries and a cabinet of curiosities.

Macabre astrological automaton clock dating to the late 1400s.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.