Unlike Rome’s Catacombs, this ossuary of between 6 and 7 million Parisian residents was created for health reasons rather than spiritual reasons. Back in the 1760s to 1770s, when city cemeteries began to ooze into the cellars of neighboring buildings, it was time to find a sollution to the health hazard.
For fifteen consecutive months, bones were carted off from the Right Bank cemeteries and dumped in the 14th arrondissement (which at that time was called Mont Rouge (Denfert-Rochereau) and Mont-souris, which is now Montsouris Park.
The underbelly of Paris has been compared to Swiss cheese (or Gruyere, if you prefer). Whichever cheese you choose, the fact remains, beneath the city of Paris, you’ll find a virtual honeycomb of tunnels. The French resistance used these tunnels during World War II and rave parties flourished during the 90s - despite the fact entering Paris’ underground without permission -is strictly forbidden. The Catacombs Museum at Place Denfert Rochereau in Paris’s 14th arrondissement is one of the exceptions to that rule.
(Note: For those that do not know their way around these tunnels, you could be lost forever - imagine trying to find your way around 300 km of tunnels without a road map - it’s hard enough above ground!)
Most of Paris' larger churches once had their own cemeteries, but city growth and generations of dead began to overwhelm them. From the late seventeenth century, Paris' largest Les Innocents cemetery (near the Les Halles district in the middle of the city) was saturated to a point where its neighbours were suffering from disease, due to contamination caused by improper burials, open mass graves, and earth charged with decomposing organic matter.
After almost a century of ineffective decrees condemning the cemetery, it was finally decided to create three new large-scale suburban cemeteries and to condemn all existing within the city limits; the remains of all condemned cemeteries would be moved discreetly to a renovated section of Paris' abandoned quarries. The use of the depleted quarries for the storage of bones, based on the idea of Police Lieutenant General Alexandre Lenoir, was established in 1786 by his successor, M. Thiroux de Crosne, under the direction of Charles Axel Guillaumot, Inspector General of Quarries.
Remains from the cemetery of Saint-Nicolas-des-Champs were among the first to be moved. Bodies of the dead from the riots in the Place de Grève, the Hotel de Brienne, and Rue Meslee were put in the catacombs on August 28 and August 29, 1788.
The catacomb walls are covered in graffiti dating from the eighteenth century onwards. Victor Hugo used his knowledge about the tunnel system in Les Misérables. In 1871 communards killed a group of monarchists in one chamber. During World War II, Parisian members of the French Resistance used the tunnel system. Also during this period, German soldiers established an underground bunker in the catacombs below Lycée Montaigne, a high school in the 6th arrondissement. (This bunker is not on the tourist route and can only be seen during an "unauthorized visit".
The underground tunnels and chambers have long posed safety problems for construction in Paris. Quarries sometimes cave in, occasionally resulting in a hole in the ground above and causing damage to buildings. To prevent this, the IGC, Inspection générale des Carrières (General Inspection of the Quarries) was established in 1777 by the government in order to monitor the current quarries and prohibit the digging of new quarries. The IGC did, however, dig observation tunnels in order to provide themselves with better access to the quarries so that they might better monitor, repair, and map the consolidated quarries.
The monitoring and consolidation work has continued to this day. Because of the number of quarries, subway tunnels, train tunnels and sewer tunnels that have been dug underneath Paris, as well as the softness of the stone involved, extra caution is taken when new construction is attempted or new tunnels are dug. However, this did not prevent problems during the digging of Paris Métro Line 14.