The Catacombs of Paris are in the running for the honor of scariest site on Earth. In narrow passageways under the City of Lights, you can find the remains of as many as 6 million people. The catacombs were originally tunnels used to mine stone. The building blocks of many famous Paris landmarks came from these subterranean quarries.
In the late 18th century, authorities began to transfer remains from overcrowded Paris cemeteries to the unused quarry tunnels. There were so many skeletons that the bones were stacked on top of each other. The macabre piles reach from the floor to the ceiling. Some bones and skulls were arranged into patterns. Tours are available for visitors who want to see this unbelievably vast collection of human remains for themselves.