This eccentric folly house was designed by Romanian thinker Bogdan-Petriceicu Hasdeu, with a helping hand from his deceased daughter's spirit.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

Something's watching you.

An impressive monument to Poland's independence.

The relics are stored in a silver reliquary, where they can be seen through glass.

An artificial hill and apparent calendric structure built in the Early Middle Ages immortalizes a legendary Polish princess.

An open-air museum of 18th-century homes and churches transported from various villages in Southern Poland.

On this Polish road, an optical illusion makes cars seem to roll uphill.

This open-air museum was originally a World War II testing ground for German missiles and rockets.

This antique thermometer honors the creator of the first universal temperature scale.