10The Catacombs, France

By the 17th century, the cemeteries of Paris were overstuffed with graves to the point when corpses could not be contained inside. People living near the cemeteries complained about the foul smell of decomposing flesh. This public health problem led to a decision to transfer the bones from the cemeteries to an underground site, which were once the quarries.

It took 12 years to move the bones of the corpses! 6 to 7 million corpses were moved in the centuries-old tunnels and were artfully arranged. Some of the oldest date back to the Merovingian era, more than 1,200 years ago. There are some of the popular characters from history who call the catacombs their resting place. Location: 1 Avenue du Colonel Henri Rol-Tanguy, 75014 Paris, France