The Nile is traditionally identified as the world's longest river, measuring about 6,650 kilometres from its most distant headwaters to the Mediterranean Sea. It flows north through northeastern Africa and has supported major civilizations for thousands of years.
The river's two best-known tributaries are 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 and supplies much of the Nile's seasonal floodwater. They meet at Khartoum in Sudan.
The Amazon is generally accepted as the world's largest river by discharge and drainage-basin size. Some modern measurements have debated whether the Amazon may be longer, depending on which source is selected, but the Nile remains the conventional answer in standard geographic references.