The Nile is the longest river in Africa, flowing for roughly 6,650 kilometres according to the commonly cited measurement. It crosses or drains parts of northeastern Africa before reaching the Mediterranean Sea.
The river has two principal tributaries commonly emphasized in geography: the White Nile and the Blue Nile. The White Nile rises in the Great Lakes region, while the Blue Nile begins at Lake Tana in Ethiopia. They meet at Khartoum in Sudan.
Nile crocodiles inhabit parts of the river system and associated wetlands, although their range extends well beyond the Nile basin. The river has supported major civilizations, agriculture and cities for thousands of years, especially in Egypt and Sudan.