The Catacombes originate from the time (under king Philippe Auguste, around 1200) when the city expanded so much that stones were badly needed. Towards the end of the 18th century a law was passed confining burial grounds to the then city outskirts. The Catacombs were the first to be founded, in 1786. A 2-km section of an extensive 300-km underground network of quarries and tunnels was selected to serve as an ossuaire (bone depository). The rotting, putrid overflow from the city’s cemeteries was transferred here and unceremoniously dumped down disused quarry airshafts. When the Catacombs were first opened to the public in 1804, the femurs, tibias and skulls were stacked in neatly patterned ‘walls’, reaching up to 2 m high and 30 m deep. This is the city’s most ghoulish – and poignant – attraction.