Mauritania is rich in rock art sites, particularly in the south eastern parts such as Guilemsi which occurs on a sandstone ridge in the Tagant District. Paintings are found in the walled shelters and on stonewall banks of a dry river. Images include camels, horsemen, cattle, wild animals and a few geometric designs belonging to the fourth and third millennia. More recent images include human figures in red riding horses or cattle with some holding weapons. Schematic designs use red, white or black colouration. Handprints and mythical animals are also depicted. Another site of significance is that of Oued Jrid (Jrid Wadi) in the south consisting of a steep-sided valley with ledges and rock-fronted shelters. Finger-painted scenes of mounted and unmounted horses in rows are common. Grotte des Écritures features herdsmen whilst M’treoka features incised boulders with engravings. The rock art covers a time from the Hunters Period: 7,000 – 2,500 BC to the Camel Period: about 100 BC.