Guinea-Bissau (Republica de Guine-Bissau) is a nation of west Africa. It has borders with Senegal and Guinea, and a coastline on the Atlantic Ocean. It has an area of 13,948 square miles (36,125 sq km) and a population of about 1.5 million. The capital city is Bissau, and the official language is Portugese. Formerly a Portugese colony, Guinea-Bissau achieved independence on 24 September 1974.