In September 1940, the entrance to Lascaux Cave was discovered by 18-year-old Marcel Ravidat. Ravidat returned to the scene with three comrades, Jacques Marsal, Georges Agnel, and Simon Coencas, and entered the cave via a long shaft. The four teenagers discovered that the cave walls were covered with depictions of animals. The cave complex was opened to the public in 1948. By 1955, the carbon dioxide produced by 1,200 visitors per day had visibly damaged the paintings. The cave was closed to the public in 1963 in order to preserve the art. After the cave was closed, the paintings were restored to their original state, and were monitored on a daily basis. Rooms in the cave include The Hall of the Bulls, the Passageway, the Shaft, the Nave, the Apse, and the Chamber of Felines.
Since 1998 the cave has been beset with a fungus, variously blamed on a new air conditioning system that was installed in the caves, the use of high-powered lights, and the presence of too many visitors. As of 2008, the cave contained black mold which scientists were and still are trying to keep away from the paintings. In January 2008, authorities closed the cave for three months even to scientists and preservationists. A single individual was allowed to enter the cave for 20 minutes once a week to monitor climatic conditions. Now only a few scientific experts are allowed to work inside the cave and just for a few days a month but the efforts to remove the mold have taken a toll, leaving dark patches and damaging the pigments on the walls.