One week after the discovery of the site, on 21 September 1940, Henri Breuil made his first visit to Lascaux to authenticate the figures in the sanctuary. He was accompanied by several prehistorians, including Jean Bouyssonie, Dr. Cheynier and Denis Peyrony, who was curator of the Museum of Prehistory in Eyzies. The following month, under Breuil's direction, an initial photographic campaign was carried out by Fernand Windels, and Maurice Thaon began to draw the figures. A number of objects made of bone and flint were found on the cave's floors and ledges; they were collected by the discoverers and during the visits made by Léon Laval and Denis Peyrony.

Development work on the cave to make it accessible to the public was completed in 1948. The initial excavations, led by Breuil and Séverin Blanc, began one year later. In the initial phase, only the Shaft was explored, no doubt in the hope that a tomb would be discovered at the foot of the Shaft Scene.