Sijilmasa (also Sijilmassa, Sidjilmasa, Sidjilmassa and Sigilmassa) was a medieval Moroccan city and trade entrepôt at the northern edge of the Sahara Desert in Morocco. The ruins of the town lie for five miles along the River Ziz in the Tafilalt oasis near the town of Rissani. The town's history was marked by several successive invasions by Berber dynasties. Up until the 14th century, as the northern terminus for the western trans-Sahara trade route, it was one of the most important trade centres in the Maghreb during the Middle Ages.