Niger River Niger River The Niger River (; , ) is the principal river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in southeastern Guinea. It runs in a crescent through Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Niger Delta or the Oil Rivers, into the Gulf of Guinea in the Atlantic Ocean. The Niger is the third-longest river in Africa, exceeded only by the Nile and the Congo River (also known as the Zaïre River). Its main tributary
Amazon River on for many years, the historic consensus of geographic authorities has been to regard the Amazon as the second longest river in the world, with the Nile being the longest. However, the Amazon has been measured by different geographers as being anywhere between long. It is often said to be "at least" long. The Nile is reported to be anywhere from . Often it is said to be "about" long. There are many factors that can affect these measurements. A study by Brazilian scientists concluded that the Amazon is actually longer than the Nile. Using Nevado Mismi, which in 2001