Constantly maintained, this organ is playing a six-century long composition by John Cage.

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

Bell tower juts out from a village buried under a lake.

An abused and forgotten metropolis, abandoned for centuries.

Jean Tinguely's bizarre monster sculpture is hidden deep in a forest.

Shattered columns and Egyptian pyramids outside of Paris.

The man who introduced reinforced concrete to the world demonstrated its genius by using it to build his own house.

1920's reinforced concrete church by architect Auguste Perret changes the face of modern design.

Paris' linguistic guide to the international language of, yes, love.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.