The bones of over 6 million people are in a burial chamber (or ossuary, as the professionals refer to it) under the romantic streets of Paris. The city cemeteries were overflowing with bodies, so these limestone tunnels were constructed to make room. Founded in the 12th century, Les Innocents was the main cemetery in the city, and its graves were often buried in large pits that could hold up to 1,500 bodies at a time. By 1780, the place was so overflowing the bodies started protruding from the ground. The city decided it was time to relocate the dead.
Two years were required to empty the cemetery (from 1785 to 1787). The bodies had to be removed and moved into old quarry wells by miners. It is believed that other Paris cemeteries started using the catacombs as well after the French revolution, turning them into a popular tourist attraction.
Located more than 60 feet beneath the city, the ossuary spans roughly 200 miles! When it opened in 1809, it became a popular attraction among royalty and gentry alike.
A large part of what attracted people to the catacombs was the decorative arrangement the bones were placed in. The miners who set the bones in their new location didn't just pile them up. They used the skeletons as decorations, covered the walls with skulls, and created other patterns with different bones. The Barrel, for instance, is famous for its tibiae and skulls, which are essentially pillars supporting the roof of one of the tunnels.
Parties have been held there, it was used as a bunker, as a secret meeting place for French revolutionaries, and even as a greenhouse for mushrooms over the years!
There is no longer a way to visit the catacombs without a guide today, and only a mile of them can be visited. The catacombs have been closed since 1955, but it was only a matter of time before thrill-seeking youngsters began to explore them. People found alternative ways to enter with or without a guide since there are such a long network of tunnels, some of which are unmapped. Still, the catacombs hold many secrets today.