Gabon is a country in west central Africa sharing borders with the Gulf of Guinea to the west, Equatorial Guinea to the northwest, and Cameroon to the north, with the Republic of the Congo curving around the east and south. Its size is almost 270,000 km² with an estimated population of 1,500,000. The capital and largest city is Libreville. Since its independence from France on August 17, 1960, the Republic has been ruled by two presidents. In the early 1990s, Gabon introduced a multi-party system and a new democratic constitution that allowed for a more transparent electoral process and reformed many governmental institutions. The small population together with abundant natural resources and foreign private investment have helped make Gabon one of the most prosperous countries in the region, with the highest HDI in Sub-Saharan Africa.