The Victoria Nile enters the north end of Lake Albert, and its waters leave that lake almost uninfluenced by their volume; in fact, Lake Albert has almost become a river, the Albertine Nile, when the water coming from the Victoria Nyanza enters the river-like end of the Albert at Magungo and then abruptly turns with full stream to the north. The Mountain Nile,[124] after leaving Lake Albert, maintains a broad, lake-like character until it enters the narrow rift valley north of Nimule in the Madi country. Along this winding gorge, which exhibits some of the finest scenery of Africa, the Nile flows over nearly a hundred miles of cataracts and descends in all about five hundred feet. At Lado (in about 5° north latitude), where it slackens and expands, the altitude of the White or Mountain Nile is about fifteen hundred feet above sea-level. At the beginning of this cataract region, north of Nimule, the Nile receives a lengthy affluent from the southeast. This is the river Asua, which drains the very mountainous but slightly arid country west of the Rudolf watershed, and north of Mount Elgon. The Asua attracted a great deal of attention in the early days of Nile exploration, owing to Speke having thought that it was an additional outlet of the Victoria Nyanza, flowing from (what is now called) Kavirondo Bay. North of Lado the Nile enters an exceedingly marshy region, which is perhaps three hundred miles from north to south and two hundred miles from east to west. This area once certainly was the site of a lake at one time as large or larger than the Victoria Nyanza. This lake was mostly fed from the west by seven or eight important streams, which to-day, with their many tributaries, unite to form that broad western branch of the Nile known as the Bahr-al-Ghazal.[125] The Bahr-al-Ghazal is little else than a great estuary which receives contributions from many big rivers. If, however, one of these is to be selected as the main stream on account of general consistency of direction, then the Bahr-al-Arab would be the upper waters of the Gazelle. The furthest perennial source of this river is in the country of Dar Fertit, on the verge of the northernmost limits of the Congo basin, and within a few days’ journey of the Upper Shari. Other very doubtful tributaries of the Bahr-al-Arab drain off what little water is not evaporated in the somewhat arid country of Darfur. The Bahr-al-Arab is fed by at least four important rivers, which flow northward from the Congo water-parting in the Nyam-nyam countries.