About three kilometres lower down than the point of influx of Wadi el Abiad, Wadi Rahaba receives the =Wadi Megah= as a tributary from the north-west; a well, called =Bir el Gahlia= is said to exist at the head of this wadi, about twelve kilometres up from its opening into Wadi Rahaba. Some six kilometres further down, Wadi Rahaba opens out; its course down to this point has been shut in by high hills, but now becomes an ill-marked drainage line over a sandy plain. The plain is broken by small hills, and is limited east and west by other hills which increase in height further away, forming in fact the foot-hills of Gebels Orga and Um Tenebda on the west and of Gebel Faraid on the east. In this part of its course Rahaba receives several tributaries, the principal being =Wadi Hutit= from the north-west, =Wadi Dagalai lil Rahaba= and =Wadi Abu Had= from the east, and =Wadi el Marafai=, which runs for some ten kilometres nearly parallel to Wadi Rahaba, among low hills two or three kilometres east of the main Wadi, joining the latter about due west of Gebel Fereyid. Wadi Rahaba curves round to the south of Gebel Fereyid in a quadrant of about seven kilometres radius, and then proceeds nearly due east to reach the sea in about latitude 23° 12′. The upper parts of Wadi Rahaba, where it is shut in by high hills, contain many trees and bushes; but the lower parts are more barren and sandy, the actual drainage line being in places difficult to define on account of the paucity of vegetation and the openness of the plain. The total length is about seventy-five kilometres, and the total fall 450 metres; the slope averages eight metres per kilometre in the upper twenty-five kilometres, where the wadi is narrow and shut in, but only five metres per kilometre in the broad and sandy course which forms the remaining fifty kilometres.