A succession of oases, each overlooked by an ancient ksar (fortress) and associated village, with palm cultivation below. Residents practice the traditional fouggara method of distributing water for irrigation, using a hydraulic system said to have been introduced to the Maghreb during the Arab conquest of the 7th century. The oasis is a refuge for sedentary wildlife, providing shelter from wind and heat. The isolation of the Site and the hostile environmental conditions have favoured the evolution of a very interesting biodiversity. Precautionary measures are necessary to avoid any loss and genetic erosion of these breeds and local varieties. Depletion of groundwater reserves, caused in part by increasing use of modern agricultural pump irrigation and monoculture, is seen as a potential threat, as is the continuous advance of ergs or wind-driven sand dunes. There is some tourism, with pedestrian and camel-back tours of the ksars and fouggara, and local crafts are in considerable demand.