The border starts in the west at the tripoint with Libya on Gabal El Uweinat and then proceeds eastwards along the 22nd parallel north to Lake Nasser.[2] The border then briefly veers northwards, creating an area known as the 'Wadi Halfa Salient', before resuming its course along the 22nd parallel out to the Red Sea just south of Cape Elba (Ras Hadarba).[2] Sudan maintains that the border diverges about 183 km (114 m) east of the salient, shifting south so as to leave Bir Tawil in Egypt, and then north-east so as to include the Halayib Triangle within Sudan. The boundary traverses a thinly populated region of the Sahara desert and Libyan desert known traditionally as Nubia, with the main population centres being around the river Nile in the vicinity of Wadi Halfa.