About the latitude of Ain el Haiss the east and west escarpments approach each other considerably, the width of the depression narrowing from some 36 to about 15 kilometres. This narrowing continues, though more gradually, to the southern extremity, where the width is only 4 kilometres. The western side, south of Ain el Haiss, is formed of three separate scarps, one behind the other, the outermost being that of white chalk which has already been referred to. On the east a second scarp of less height is found behind the lower. The height of the main scarp above the oasis floor at the southern end of the oasis is about 80 metres. At the extreme south the main road from Baharia to Farafra ascends up an easy gradient to the plateau above the lowest escarpment, the others being crossed further to the south. _The Hills within the Oasis-excavation._—The most striking feature in the topography of Baharia Oasis is the large number of hills within the area. These hills impede the view, so that from very few points on the low ground can any extended outlook be obtained, and they give to Baharia an appearance entirely different from that which characterises the other Egyptian oases. For the most part these hills have a black aspect, due to the nature of the rocks (ferruginous quartzites and dolerite) capping them; a few are reddish (ferruginous sandstone and ochreous clay); others again are white (limestone). The most strongly-marked group of hills is that extending in a nearly straight north-easterly direction a few kilometres south of the villages. Forming a prolongation of the long tongue of the west scarp already mentioned, this line of hills almost cuts the oasis in two. The largest hill of the range, Jebel Hefhuf, a narrow, ridge-like hill of limestone, has a black appearance at its northern end, being here composed of dolerite; the others capped entirely by brown limestone and partly swathed in accumulations of blown sand are of lighter aspect. They rise to a height of some 130 metres above the level of the villages. The large, dark, dolerite-capped hill between El Qasr-Bawitti and Zubbo-Mandisha (Jebel Mandisha) divides the two main cultivated tracts of the oasis from each other, the road from Mandisha to El Qasr passing over its southern end. A similar mass is Jebel Mayesra, the large triangular hill north of Jebel Mandisha; the blackness of Jebel Horabi, in the north end of the oasis, is, on the other hand, due not to eruptive rocks but to the presence of iron ore in considerable quantity.