The Nile is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The longest river in Africa, it has historically been considered the longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer. The Nile is amongst the smallest of the major world rivers by measure of cubic metres flowing annually. About 6,650 km (4,130 mi) long, its drainage basin covers eleven countries: Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, Republic of the Sudan, and Egypt. In particular, the Nile is the primary water source of Egypt, Sudan and South Sudan. Additionally, the Nile is an important economic river, supporting agriculture and fishing.
The Nile has two major tributaries – the White Nile, which begins at Jinja, Lake Victoria, and the Blue Nile. The White Nile is traditionally considered to be the headwaters stream. However, the Blue Nile is the source of most of the water of Nile downstream, containing 80% of the water and silt. The White Nile is longer and rises in the Great Lakes region. It begins from Uganda Lake Victoria, Uganda and South Sudan. The Blue Nile begins at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet at the Sudanese capital of Khartoum.
The northern section of the river flows north almost entirely through the Sudanese desert to Egypt, where Cairo is located on its large delta, and the river flows into the Mediterranean Sea at Alexandria. Egyptian civilization and Sudanese kingdoms have depended on the river and its annual flooding since ancient times. Most of the population and cities of Egypt lie along those parts of the Nile valley north of Aswan dam. Nearly all the cultural and historical sites of Ancient Egypt developed and are found along river banks. The Nile is, with the Rhône and Po, one of the three Mediterranean rivers with the largest water discharge.