For more than 100 km (62 miles) the Drâa Valley (Vallée du Drâa) oasis turns the brown desert a lush green. An important transit point on the trans-Saharan caravan route and from the late 8th century an important center for Jewish civilization, the valley is noted for its splendid kasbahs. The Wadi Drâa, once the longest river in Morocco, no longer flows to Agadir on the Atlantic but runs dry near M’hamid.