East of Tinerir is the Ziz Valley and Tafilalet region, where Jews lived and financed the caravan trade with Sub-Saharan Africa from as early as the eighth century. Errachidia is a town surrounded by dozens of ksour, or fortified villages, where Jews once coexisted with Berber tribes. Erfoud was the major Jewish population center of the Tafilalet, where Jews worked as merchants and artisans as late as the twentieth century. The Jewish cemetery is sandy but otherwise well-preserved. South of Erfoud are the ruins of Sijilmassa, the first town founded by the Arabs in Morocco. Beginning in the eighth century, Sijilmassa became an important intellectual and commercial center for both Jews and Arabs.  The near-by town of Rissani is the ancestral home of the ruling Alaouite dynasty, and contains the mausoleum of the dynasty's founder, Moulay Ali Charif. The fortified towns and villages of the area are striking examples of how Jews lived for centuries with the Arabs of the region. The Jewish cemetery is unenclosed, facing the walls of the town.