Image: Lascaux by Prof saxx via Wikimedia Commons
The Vézère Valley contains some of the Dordogne's most important archaeological sites, including 25 prehistoric decorated caves, chief among which must be the extraordinary hand-painted Caves of Lascaux, dating from Palaeolithic times and admired for the rich colour used in the drawings and the surprising detail with which the figures have been represented.
The Vézère Valley comprises 147 important prehistoric sites, and is now protected by UNESCO as a World Heritage Site. Aside from the paintings, there have also been skeletons, flints, utensils and other forms of art and objects discovered as well. These are now on display in the National Prehistory Museum which is located in the old castle of Les Eyzies-de-Tayac, which is a commune roughly midway between Constant and Lascaux.
Though the Lascaux caves are out of bounds, there are many sites in and around Eyzies-de-Tayac still open for visitors. The cave of Roc de Saint-Cirq is still open and there is a little museum to visit too. The paintings in the Font-de-Gaume date from around 14,000 BCE, but do bear in mind that a reduction in the amount of visitors permitted per day means the only way you'll be able to visit this particular cave is to buy a ticket on the day. Some of the stunning rock dwellings around this town range from as long ago as 40,000 years. You can find more information on all the attractions in Eyzies-de-Tayac on the tourist website here.