Geography of Africa outer ranges. The main drainage of the continent is to the north and west, or towards the basin of the Atlantic Ocean. To the main African rivers belong: Nile (the longest river of Africa), Congo (river with the highest water discharge on the continent) and the Niger, which flows half of its length through the arid areas. The largest lakes are the following: Lake Victoria (Lake Ukerewe), Lake Chad, in the centre of the continent, Lake Tanganyika, lying between the Democratic Republic of Congo, Burundi, Tanzania and Zambia. There is also the considerably large Lake Malawi stretching along the eastern
Nile monitor Nile monitor The Nile monitor ("Varanus niloticus") is a large member of the monitor family (Varanidae) found throughout much of Africa, but is absent from the west, where it is replaced by "Varanus stellatus". Other common names include the African small-grain lizard, water leguaan or river leguaan (leguan, leguaan, and likkewaan mean monitor lizard in South African English, and can be used interchangeably). Nile monitors can grow to about in length, with the largest specimens attaining . In an average-sized specimen, the snout-to-vent length will be around . In body mass, adults have been reported to vary widely, one study