Lascaux is the name given to a number of caves in southwestern France famous for their cave paintings. The original caves are located near the village of Montignac, in the Dordogne département. They contain some of the most well-known Upper Paleolithic art. These paintings are estimated to be 26,000 years old. They primarily consist of realistic images of large animals. Many of these animals are known from fossil evidence to have lived in the area at the time. Lascaux was added to the UNESCO World Heritage Sites list in 1979.
The caves were discovered in 1940. By 1955, about 2000 people visited them every day. In 1968, the original cave was closed to the public, and a system of air conditioning was installed. The cave paintings were restored and replicas of several paintings were created in another cave nearby. Today, the original cave is no longer accessible to the public.
In 2000, another problem emerged: Certain kinds of fungi started to grow in the original cave. These are extremely resistant to the usual fungicides used, even to formaldehyde. The fungus lives in symbiosis with a bacterium which is capable of destroying the fungicide. Therefore, the fungicide needs to be combined with an antibiotic to kill the bacterium as well.
As of 2006, the situation is more or less under control. The original caves are now sprayed with the fungicide/antibiotic every fortnight. Special workers need to clear the cave walls by hand, removing the mycelium which grows despite the treatment.