Barcelona (Catalan IPA: [bəɾsəˈlonə], Spanish IPA: [baɾθeˈlona]) is the capital an most populous city of Catalonia and the second largest city in Spain, with a population of 1,605,602 in 2006, while the population of the Metropolitan Area was 3,161,081. It is the central nucleus of the Urban Region of Barcelona, which relies on a population of 4,856,579. It is located on the Mediterranean coast (41°23′N, 2°11′E) between the mouths of the rivers Llobregat and Besòs and is limited to the west by the Serra de Collserola ridge (512 m/1,680 ft).