This small chapel holds the mummified heart of one of the heroes of the Greek Revolution.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

The ruins of an ancient mansion sits in front of and underneath a contemporary art gallery.

Where commuters walk through remnants of an ancient Greek necropolis.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

The last remaining predreadnought battleship in the world has been a museum for nearly a century.

Once the most densely populated place in the world, this island is now a ghost town.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This retro underwater observation tower would make the perfect lair for a sea-loving villain.