Mines Of Tunnel Network, Catacombes De Paris, Paris, France

By the end of the same century "Saints Innocents" was neighbour to the principal Parisan Les Halles marketplace, and already filled to overflowing. To make room for more burials, the long-dead were exhumed and their bones packed into the roofs and walls of "charnier" galleries built to the inside of the cemetery walls. By the end of the 18th century, the central burial ground was a two metre high mound of earth filled with centuries of Parisian dead from disease, famine, and wars, plus the remains from the Hôtel-Dieu hospital and the Morgue; other Parisian parishes had their own burial grounds, but the conditions in Les Innocents cemetery were by far the worst.
A series of ineffective decrees limiting the use of the cemetery did little to remedy the situation, and it was not until the late 18th century that it was decided to create three new large-scale suburban burial grounds on the outskirts of the city, and to condemn all existing parish cemeteries within city limits.
• Former mines in Paris
The Left Bank rests upon rich Lutetian limestone deposits. This stone built much of the city, but it was extracted in suburban locations away from any habitation. Because of the post 12th-century haphazard mining technique of digging wells down to the deposit and extracting it horizontally along the vein until depletion, many of these (often illicit) mines were uncharted, and when depleted, often abandoned and forgotten. Paris had annexed its suburbs many times over the centuries, and by the 18th century many of its arrondissements (administrative districts) were or included previously mined territories.