The Main cave of Ménieux, known as Gavechou, opens with a portico about 12 m wide. It is 15 m deep and extends eastward by a corridor 3 to 4 m wide and 30 m long that opens into the meadow at a flooded place during high water. This cave was occupied from the Mousterian to the Iron Age. Gustave Chauvet discovered and excavated it from 1869 to 1894. The terrace was composed of a mixture of fauna and objects of very different ages, reindeer teeth and pottery, Solutrean notch arrow, and Mousterian scrapers.

In the cave, he found five layers, with layer 2 dating from the Solutrean and layer 3 dating from the Mousterian with bones of bovids, equids, reindeer, hyenas, and beaver. The presence of Périgordian is discussed.

The corridor delivered a lithic industry belonging to the Magdalenian or Solutrean.

The cave of the Ménieux also delivered a human jaw.