The Nile flows through Cairo and forms a vast delta in northern Egypt.
The river runs northward through northeastern Africa before entering the Mediterranean Sea. Its two principal tributaries are the White Nile, which rises in the Great Lakes region, and the Blue Nile, which begins at Lake Tana in Ethiopia. They meet at Khartoum in Sudan.
For thousands of years, the Nile's seasonal floods deposited fertile silt across Egypt's valley and delta. Modern dams, especially the Aswan High Dam, regulate water and reduce natural flooding. The Nile is often described as the world's longest river, although some measurements comparing it with the Amazon produce a different result.