=Wadi Gemal= is the terminal portion, about sixty kilometres in length, of the main drainage channel from a basin nearly 200 square kilometres in area. With its numerous large feeders, the principal of which is Wadi Huluz, about eighty kilometres in length, the Wadi Gemal drains the Hafafit and Nugrus ranges of mountains on the north, and a great mass of high mountains, including Gebel Hamata, on the south. It will be convenient here to describe only the Wadi Gemal proper, leaving the great wadis which join to form it, and its major tributaries, for separate treatment. The name Wadi Gemal is first given to the drainage at the point where Wadi Huluz turns sharply eastward in longitude 34° 39′.[89] At this point the country becomes more open than in the gorge-like Wadi Huluz. To the north is a mass of low granite hills, some of which have remarkable shapes, with a great deal of drift sand, while to the south are the higher dark hills flanking Gebel Um Suerab. Among these surroundings the wadi pursues a winding course, with a general north-easterly direction, receiving the Wadi Um Suerab lil Gemal and the Wadi Durunkat as tributaries from the south. About six kilometres below the point of influx of Wadi Durunkat, on the right (south) side of Wadi Gemal, is a locality called =Geli=, where there are extensive ruins. A very remarkable rock in the middle of the main wadi marks the place whence a track leads south-east past the ruins and across the heads of Wadis Um Ghazal and Mukhatatat into the upper part of Wadi el Abiad. Passing a remarkable bell-shaped hill (Gebel Um Regeba, rising to 571 metres above sea, the “mosque rock” of Floyer’s map) about four kilometres on the left, Wadi Gemal receives two small feeders coming from among the hills to the south, and then the important tributary called Wadi Hafafit enters from the north-west.