Wadi Hanifa, historically known as Wadi al-Arad, is a wadi in the Najd region, Riyadh Province, in central Saudi Arabia. The valley runs for a length of 120 km from northwest to southeast, cutting through the city of Riyadh, the capital of Saudi Arabia. A string of towns and villages lie along the valley, including Uyaynah, Irqah and Diriyah.