The Niger River (/ˈnaɪdʒər/ NY-jər; French: (le) fleuve Niger, pronounced: [(lə) flœv niʒɛʁ]) is the principal river of western Africa, extending about 4,180 km (2,600 mi). Its drainage basin is 2,117,700 km2 (817,600 sq mi) 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 is the Benue River.
The Scottish explorer Mungo Park was the first Westerner known to have travelled to the central portion of the Niger River.
The Niger is called Jeliba or Joliba "great river" in Manding; Orimiri or Orimili "great water" in Igbo; Egerew n-Igerewen "river of rivers" in Tuareg; Isa Ber "big river" in Songhay; Kwara in Hausa; and Oya in Yoruba. The earliest use of the name "Niger" for the river is by Leo Africanus in his Della descrittione dell’Africa et delle cose notabili che iui sono published in Italian in 1550. The name may come from Berber phrase ger-n-ger meaning "river of rivers". As Timbuktu was the southern end of the principal Trans-Saharan trade route to the western Mediterranean, it was the source of most European knowledge of the region.