Nadar, View in the Catacombs, 1861

A network of underground tunnels on the site of ancient Roman quarries near Paris, part of an ancient tunnel system covering 800 hectares. Between the late 18th and mid-19th centuries, the remains of some 6 million people were brought here as part of an effort to relieve overcrowded city cemeteries. The total area of the underground cemetery is 11,000 m2. Today the catacombs are part of the Carnavale Museum and part of the site is open to the public. More than 500,000 people visit the catacombs every year.