The longest river in the world is the Nile River, stretching approximately 6,650 kilometers (4,130 miles). It flows through eleven countries in northeastern Africa, including Uganda, Sudan, and Egypt, before draining into the Mediterranean Sea. Historically, the Nile has been vital to the development of ancient Egyptian civilization, providing water, transportation, and fertile land for agriculture. The river is composed of two major tributaries: the White Nile and the Blue Nile. While there is an ongoing debate about whether the Amazon River might be longer, the Nile's cultural and historical significance remains unparalleled in the context of human civilization.