Νείλου, or the Nile River, is the longest river in the world, stretching about 6,650 kilometers (4,130 miles). It flows through eleven countries in northeastern Africa, including Egypt and Sudan, before emptying into the Mediterranean Sea. The river is vital for agriculture, providing water to arid regions and supporting the livelihoods of millions. The Nile has two main tributaries: the Blue Nile, which originates in Ethiopia, and the White Nile, which begins in Uganda. Together, they converge in Sudan to form the Nile. The river has played a crucial role in the history and culture of ancient civilizations, particularly in Egyptian society.