GuineaGuinea, officially the Republic of Guinea , is a country in West Africa named after the Guinea River. Formerly known as French Guinea (French: Guinée française), the modern country is sometimes referred to as Guinea-Conakry.Conakryis the capital and largest city of Guinea. Conakry is a port city on the Atlantic Ocean and serves as the economic, financial and cultural centre of Guinea.The Niger Riveris the principal river of western Africa, extending about 4,180 km (2,600 mi). Its source is in the Guinea Highlands in southeastern Guinea. It runs in a crescent through Guinea, Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Guinea Delta or the Oil Rivers, into the Gulf of Guinea in the Atlantic.The Gambia River(formerly known as the River Gambra) is a major river in West Africa, running 1,130 kilometres (700 mi) from the Fouta Djallon plateau in north Guinea westward through Senegal and the Gambia to the Atlantic Ocean at the city of Banjul.