The Aïn Beni Mathar-Guefaït region lies in the northwestern extreme of a great physiographic unit of the Maghreb. In the north of this region, the Guefaït 4 site offers an assemblage of large mammals, including elephants, rhinoceros, hippopotamus and, above all, a primitive species of horse, Hipparion. This community of mammals is accompanied by a sizable number of rodents and reptiles, dominated by a giant turtle, which places the site at the start of the Quaternary, with a lake set in a savanna environment. In the center of the valley, the sites of Aïn Tabouda and Garat Soultana contain anthropic industry of the so-called Mode 1, a technology documented for the first time in stratigraphic environments in Morocco. This industry is contained in fluvial levels that indicate moments of strong circulation of water. The CENIEH is leading research into the geochronology and geomorphology of the Aïn Beni Mathar–Guefaït project.