The =Wadi Abu Debebi lil Betan=, which joins Betan on the north about three kilometres below the wells, leads by an easy pass into =Wadi Abu Debebi lil Khoda=, one of the heads of Wadi Khoda, and forms the nearest way to the coast from Bir Betan. =Wadi Abu Sieiyil= is a small feeder entering Betan from the south, three kilometres further down. The principal remaining tributaries of Betan are the Wadis Hefeiri, Abu Beid, and Egat. =Wadi Hefeiri= runs westward from near the Abu Debebi pass, and turning south near Gebel Hendusi, receives the =Rod el Hendusi= just before entering Betan. =Wadi Abu Beid el Azrak= originates near Gebel Abu Sieiyil west of Abu Dahr, and flows southwards to join =Wadi Abu Beid el Abiad=, which in turn flows into Wadi Betan. A well, =Bir Abu Beid=, is situated near the junction of Wadi Abu Beid el Abiad and Wadi Abu Beid el Azrak, where there are numerous seyal trees; it was yielding a fair quantity of good water in 1906. Of the =Wadi Egat=, nothing has been seen; it is, however, stated by the Arabs to originate in the rugged hilly tract south of Gebel Abu Dahr, and to join Wadi Betan lower down its course than Abu Beid. =Wadi Dif= originates in the sandstone hills round Bir Dif, and pursues a very sinuous north-easterly course, cutting through the high sandstone plateau which is named Gebel Hodein to the north, and Gebel Dif to the south of it. For the major part of its length of twenty-nine kilometres it is very narrow, with very high steep sandstone scarps on either side, but it is a little more open near its origin, where Wadi Feqoh joins it, and in its lower part it winds as a broad sandy valley through the low hills which separate the Wadi Hodein from the high sandstone plateaux; it joins Wadi Hodein close to the meridian of 35°. Except the Wadi Feqoh, which is of immense length, and drains a very large area, Wadi Dif has only a few insignificant feeders. Of these, =Talet Um Karaba= and =Wadi Enqireidia= enter from the south plateau near the place where Wadi Dif leaves the high sandstone hills; and =Wadi Gelabat Shabai=, coursing north-east through the low hill country flanking the plateau, joins Wadi Dif just above its junction with Hodein. =Bir Dif= is situated in a small gully forming the head of Wadi Dif, in latitude 23° 12′ 42″. To a traveller coming up Wadi Dif, Wadi Feqoh forms the main continuation of Wadi Dif, and the gully containing Bir Dif appears to be a lateral tributary coming in from the west; but the Arabs restrict the name Dif to the drainage line below the spring, and apply the name Feqoh to all the upper main channel. Bir Dif is a spring forming two pools of good water, situated about a kilometre up the gully, at the junction of sandstone and schists. The approach to the pools is very stony, but camels can easily reach the water; the spring is 290 metres above sea-level.