Charleroi is a city and a municipality of Wallonia, located in the province of Hainaut, Belgium. It is the largest city in both Hainaut and Wallonia. The city is situated in the valley of the Sambre, in the south-west of Belgium, not far from the border with France. By 1 January 2008, the total population of Charleroi was 201,593. The metropolitan area, including the outer commuter zone, covers an area of 1,462 square kilometres (564 sq mi) with a total population of 522,522 by 1 January 2008, ranking it as the 5th most populous in Belgium after Brussels, Antwerp, Liège, and Ghent. The inhabitants are called Carolorégiens or simply Carolos.