Paris is often called La Ville Lumière (meaning ‘The City of Light’), however, beneath this bustling city, lies a dark subterranean world holding the remains of 6 million of its former inhabitants. This beautiful old ossuary was fascinating to explore. The tunnels are nearly 300 kilometres long. The area in and around Paris has been permanently occupied since the Roman era. When Paris was part of the Roman Empire, people buried their dead on the outskirts of the city. Parisians changed to internments in consecrated burial grounds within the city after the rise of Christianity. Cimetière des Innocents, or the Cemetery of the Innocents, was the oldest of these church graveyards. The corpses from eighteen parishes, two hospitals, and the city morgue were all buried here. By the 14th century, corpses were stacked on top of each other for meters underground and others had to be interred in mass graves. The problem became so bad in the 18th century, after ten centuries of burials and decay, that bodies could no longer skeletonize in the soil. Many of the corpses saponified, fatty tissue turned into a soap-like substance, or putrified in huge holes, producing a rotting smell. The historic cemetery became a source of disease and infection. In 1763 Louis XV issued an edict forbidding all burials inside the city. Then in 1786 a city commission decided to exhume the graves from the city’s graveyards and store the bones in the abandoned quarries beneath the capital, starting with the the Cemetery of the Innocents.