The longest river in the world is the Nile River, which stretches approximately 6,650 kilometers (4,130 miles) through northeastern Africa. Flowing through several countries, including Uganda, Sudan, and Egypt, the Nile has been historically significant for agriculture and civilization, particularly in ancient Egypt, where it provided fertile land and resources. The river has two primary tributaries: the White Nile and the Blue Nile, which converge in Sudan. Recently, the Amazon River has also been considered for this title due to varying measurement methods, but the Nile generally retains the distinction of being the longest river.