The Catacombs of Paris are underground ossuaries in Paris, France which hold the remains of over six million people in a small part of the ancient Mines of Paris tunnel network.Located south of the former city gate "Barrière d’Enfer" (Gate of Hell) beneath Rue de la Tombe-Issoire, the ossuary was founded when city officials were faced with two simultaneous problems: a series of cave-ins starting in 1774 and overflowing cemeteries, particularly Saint Innocents.