The Catacombs of Paris are an underground ossuary located in Paris, France. They were created in the late 18th century to address the city's overflowing cemeteries. The catacombs hold the remains of approximately six million people, transferred from various burial sites to this subterranean network of tunnels. Visitors can explore a small section of the catacombs, which feature walls lined with skulls and bones. The site is a popular tourist attraction, offering a unique glimpse into the city's history and its approach to dealing with death and burial practices during a time of crisis.