The Nile flows through Cairo and forms a vast delta before reaching the Mediterranean Sea.
The Nile is traditionally described as the world’s longest river, although measurements can vary depending on how its source and mouth are defined. It runs northward through northeastern Africa, with its principal headwaters associated with the White Nile and Blue Nile. The Blue Nile rises in Ethiopia and contributes much of the river’s seasonal sediment and flow, while the White Nile provides a steadier supply from the Great Lakes region.
Ancient Egyptian civilization developed along the river’s floodplain, where annual inundation deposited fertile silt. The Aswan High Dam, completed in the 1960s, greatly reduced natural flooding and created Lake Nasser, while also enabling large-scale water storage and hydroelectric power. At Cairo, the river divides downstream into branches that create the Nile Delta, a densely populated agricultural region. The Nile’s waters remain central to Egypt, Sudan, Ethiopia, and other countries in its basin.