Figuring out the age of cave art is fraught with difficulties.
Radiocarbon dating has long been the method of choice, but it is restricted to organic materials such as bone and charcoal.
Since the year 2000, Lascaux 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 2006, the situation became even graver - the cave saw the growth of black mold.
Lascaux is a complex cave with several areas (Hall of the Bulls, Passage gallery) It was discovered on 12 September 1940 and given statutory historic monument protection in december of the same year.
In 1979, several decorated caves of the Vézère Valley - including the Lascaux cave - were added to the UNESCO World Heritage Sites list.
Other archaeologists have argued that artists could have entered Chauvet much later and picked up charcoal that had been lying around for thousands of years.