From 1786, in the effort to eliminate the Paris overflowing cemeteries, the city decided to move the remains to underground tunnels, part of the abandoned quarries. The underground ossuary was established. Today it holds remains of over six million people.
The stone quarries opened in the 1st century, during the Roman times. Extraction of stone went underground during Middle Ages. Notre-Dame Cathedral and many other churches in Paris were built with the Lutetian limestone quarried here.
