 Later, during Quaternary glaciation, as glaciers swept by, they further deepened those valleys which would eventually (at the end of the last glaciation) be invaded with sea and become calanques.The Cosquer cave is an underwater grotto in the Calanque de Morgiou, underwater, that was inhabited during Paleolithic era, when the sea level was much lower than today.Its walls are covered with paintings and engravings dating back to between 27,000 and 19,000 BC, depicting animals such as bison, ibex, and horses, as well as sea mammals such as seals, and at least one bird, the auk.