During the glacial periods of the Pleistocene, the shore of the Mediterranean was several kilometers to the south and the sea level up to 100 m (330 ft) below the entrance of the cave.

In June 1990, Cosquer enlisted Belgian cave divers Bernard and Marc Van Espen, who located the entrance 37 meters below the Pointe de la Voile near Cap Morgiou.

They followed the gallery carefully to avoid disturbing silt and reached the underground lake Cosquer had seen, but their guide line ran out, forcing them to turn back.

This finding spurred several dives in July and August, leading to the discovery of additional cave paintings and the production of photographs and films with the help of Thierry Pelissier and Gilles Sourice.

[14] Between 2001 and 2005, and again from 2010 to 2015, a series of archaeological research operations led by Luc Vanrell, with contributions from Michel Olive, further studied the cave.

[18] The first phase, from around 27,000 years BP (the Gravettian Era), is represented by art consisting of 65 hand stencils, 44 in black and 21 in red.

Art from the more recent period dates to 19,000 years BP (the Solutrean Era) and features much more complex depictions of various animals and human figures.

There is also the more unusual depiction of 16 marine animals including 9 seals and 3 great auks as well as some jellyfish and various figures which could be either fish or cetaceans.