Africa's Nile River flows northward, emptying into the Mediterranean Sea. The Nile's two main tributaries are the Blue and White Nile Rivers, which originate in Ethiopia and Eretria's highlands and the Equatorial Lakes Region, respectively.
According to American University, the Nile, which is the world's longest river, is a lifeline for some 123 million people. The Nile River is a major source of water for irrigated agriculture, a technological practice that humans have been using for centuries. The Nile flows northward from its original sources in central Africa and empties into the Mediterranean Sea at its terminating point in Egypt.