Down below the “city of love” lies an old quarry. Once used to gather stone to build the city, it now holds a much more grim assignment. 

Long ago in Paris, the buildings required stone to be built. To obtain this material, they created tunnel-style quarries in what was then the suburbs of Paris. After some time, the city grew and expanded to where these quarries were, and buildings were built on top of them. This created unsafe conditions for the structures built there. 

In the year 1774, a very large sinkhole opened in Rue de l’Enfer. This sinkhole consumed a substantial number of buildings and homes, including several people who fell 84 feet to their death. Sadly, this was not the only time that this whole sinkhole ordeal happened, as it happened multiple times in the coming years. This forced King Louis XVI to create a task force whose job was to purely map and maintain the quarries. The Chief Inspector Charles-Axel Guillaumot then began looking for things to reinforce these quarries.

At the same time as these sinkholes, there was also a problem with the overcrowding of the city’s cemeteries. For the majority of residents, when they died, they would go to the church’s cemetery that they belonged to. “The graves were left open until they were full, a process that could take months. ‘The bodies would break down over the course of five years, then the grave would be re-opened, the bones extracted and moved to a charnel house,’ said Dr. Erin-Marie Legacey,” mentioned Jessica Rotondi of the History Channel in her article. As the city grew, the demand for a spot in the cemetery grew as well. Eventually, it got to the point where the cemeteries didn’t have any more space. This is where the quarries re-enter. 

The quarries needed materials, and the cemeteries needed a place to dispose of the mountains of bodies they were receiving, so they decided to start to pile bodies into the quarries. This converted the quarries into an ossuary (a space where the bones of humans are placed). This is now the largest ossuary in the world, and though estimates vary, many believe that the remains of over 6 million people are in the Catacombs of Paris.