Rissani region is well worth your time; local authorities have put up road signs for a touristic route, some 21 km long. It is a nice 5 hour walk, or a swift drive by car.
It will lead you by several ksours and relaxed villages. The first important one is the Zawiyya of Moulay Ali Sharif, the founder of the Alouite Dynasty; it comes about 2.5 km out of Rissani town. Next to it, there is the Ksar Abar, which was the place for unwanted members of the royal family. About 2 km further is the Ksar Ouled Abdelhalim, with its huge ramparts.
Thereafter, there are fairly few clear attractions before the scant remains of the ancient capital of Sijilmassa.