The city of Paris is old, and one of its mysterious aspects is its underground, part of which evolved into the catacombs. That term literally means ‘underground cemetery,’ deriving from Greek (cata or beneath) and Latin (tumba, or tomb). In the first three centuries AD, Romans, Etruscans, Jews and Christians used existing underground galleries to inter their dead. Early Christian martyrs in particular were inhumed that way. In Paris Roman repression drove Christians to practise their faith underground into caverns and galleries that were the unintended consequence of quarrying gypsum and limestone from beneath the surface of the city. Those galleries run about 60 feet below the surface and they extend into most of the Left Bank, between Odeon and Montsouris, as well as up to northeast Paris, beneath Montmartre, Belleville and Menilmontant. The combined length is 280 kilo-meters! Eventually, they became the resting place of about six million corpses, including the contents of the main Paris cemetery, which was called ‘The Holy Innocents.’ By 1786 that cemetery was so filled beyond capacity that people in its neighbourhood were nauseated by its stench and toxic odours. The collapse of a cellar wall exposed a large number of corpses, and spurred the authorities into evacuating the contents into the catacombs and new cemeteries beyond the city limits (Montmartre, Pere Lachaise and Montparnasse). Today you can visit the central ossuary, starting from Denfert Rochereau plaza in the 14th district. To see that very unusual place, you need to be patient: expect up to a one hour queue during peak periods for a visit that lasts 45 minutes. Be warned: once you start the guided tour, passing under the ominous inscription, “Here begins the kingdom of the dead,” there is no turning back. You have to complete the entire 2 kilo-meter underground circuit to exit. The path is often dark, sometimes quite narrow, in close proximity with skulls and bones, and not for the claustrophobic or the faint of heart. The walk, otherwise, is easy. 
Bones of the ancient cemetery of the Madeleine
The circuit represents half of one percent of the total underground galleries, some of which is still unexplored. Moreover, most of the ensemble is not an ossuary, although there are numerous small ones. The public circuit will be closed from January 9, 2017, for repairs. CATACOMBS OF PARIS: 1 av. du Colonel Henri Rol-Tanguy – 75014 Paris – Metro 6 Denfert-Rochereau/ RER B Entrance: 12euros, 5 euros for children aged 4-17. Adult with audio guide: 27 euros Opening hours : Tuesday to Sundays 10am to 8:30pm, last entries at 7:30pm. Open July 14th, November 1st and November 11th. Closed on Mondays, also May 1st and August 15th D.A