The Nile is the river that flows through Cairo and forms a delta on Egypt's Mediterranean coast.
The river runs northward through northeastern Africa. Its two principal tributaries are the White Nile, whose headwaters are in the Great Lakes region, and the Blue Nile, which rises in Ethiopia. They meet at Khartoum in Sudan before the main river continues toward Egypt.
In Egypt, the Nile passes through Cairo and divides into distributaries across the fertile Nile Delta. This annual floodplain supported agriculture and helped make ancient Egyptian civilization one of the world's earliest complex societies.
The Nile was traditionally regarded as the world's longest river, although modern measurements and differing definitions have produced debate with the Amazon. That dispute does not change the river's central geographical role in Egypt or the unmistakable identity of the Cairo waterway.