=Wadi Feqoh=, a tributary of Wadi Dif, is many times longer than Wadi Dif itself, and even longer than the Wadi Hodein of which Wadi Dif is a tributary, having a length along its main channel of 150 kilometres, with feeders totalling several times that length. Though only portions of Wadi Feqoh have been surveyed in detail, the position of its entire course is known with tolerable accuracy from the statements of guides at various stations from which portions of it could be pointed out. It is for the most part a very barren wadi, forming an ill-defined drainage line through a dreary waterless sandy waste. Its very name, which means “devoid of nourishment,” indicates its character. It originates near the west side of Gebel Soaorib, only some twenty kilometres north of the 22nd parallel of latitude, where the main watershed separates it from the feeders of the Wadi Alaqi. From here it follows a north-westerly course, passing between the mountains of Eir Arib and Hadal Derqa. Curving slightly to the north, it crosses the great sandy plain west of Gebel Korabkansi, and passes close west of the isolated mountain called Gebel Shabih. Further on, it enters a country of low hills with sandy interspaces, passing close west of the low range called Gebel Um el Kalala, and then sweeps round in a great curve towards the east to join the Wadi Dif close to Bir Dif. The fall of its bed from near Gebel Shabih to its junction with Wadi Dif, that is, in a length of seventy-two kilometres, is from 470 metres to 280 metres above sea, giving an average slope of only about 2·6 metres per kilometre; Wadi Feqoh has in fact the most gentle gradient of all the great seawards-draining wadis. Wadi Feqoh has many tributaries. Those near its head, and others coming in from the western mountains through the low hill country north of Gebel Mishbih, have not been traced; but those draining Gebel Korabkansi and Gebel Niqrub, which are probably the most important, have been mapped in detail. Most of the drainage from these localities eventually finds its way into the great trunk feeder of Wadi Feqoh, called the =Wadi Gimal=,[98] which joins Wadi Feqoh about sixteen kilometres before its junction with Wadi Dif. The tributaries of Wadi Feqoh are of much more interest than Wadi Feqoh itself, as they contain in many places a fair or even relatively rich assemblage of trees and bushes, and at least one good well, Bir Sararat Seyet. The most southern tributaries of Wadi Feqoh which have been mapped are =Wadi Kamoyib=, draining eastward from Gebel Wadhait, and =Wadi Tawayib=, draining the east face of Gebel Korabkansi. These are for the most part barren wadis each coursing for about sixteen kilometres across a sandy plain to join Feqoh.