Uruguay.(official full name in Spanish: República Oriental del Uruguay; Spanish pronunciation: [reˈpuβlika oɾjenˈtal ðel uɾuˈɣwai], Oriental Republic of Uruguay) is a country located in the southeastern part of South America. It is home to 3.46 million people, of whom 1.7 million live in the capital Montevideo and its metropolitan area. It is bordered by Brazil to the north, by Argentina across the bank of both the Uruguay River to the west and the estuary of Río de la Plata to the southwest, and the South Atlantic Ocean to the southeast. Its surface is 176.215 km² being by its territorial extension the second smallest country in South America, larger only than Suriname and the French overseas department of French Guiana. Montevideo was founded by the Spanish in the early 18th century as a military stronghold. Uruguay won its independence in 1825-1828 following a three-way struggle between Spain, Argentina and Brazil. It is a constitutional democracy, where the president fulfills the roles of both head of state and head of government. The economy is largely based on agriculture (making up 10% of GDP and the most substantial export) and the state sector, Uruguay's economy is on the whole more stable than in its surrounding states, and it maintains a solid reputation with investors. According to Transparency International, Uruguay is the second least corrupt country in Latin America (after Chile), with its political and labor conditions being among the freest on the continent. In November 2007 it became the first Latin American country and the second in all of the Americas (after Canada) to recognize same-sex civil unions at the national level. 94.6% of the population are of European descent. 66% of Uruguayans are declared Roman Catholics. Uruguay is South America's most secular country, where there is no official religion, and in which church and state are separate. At 176,214 square kilometres (68,036 square miles) of continental land and 142,199 square kilometres (54,903 sq mi) of jurisdictional waters and small river islands, Uruguay is the second smallest sovereign nation in South America (after Suriname) and the third smallest territory (French Guiana is the smallest). The landscape features mostly rolling plains and low hill ranges (cuchillas) with a fertile coastal lowland. A dense fluvial network covers the country, consisting of four river basins or deltas; the Río de la Plata, the Uruguay River, the Laguna Merín and the Río Negro. The major internal river is the Río Negro ('black river'). Several lagoons are found along the Atlantic coast. The highest point in the country is the Sierra de las Animas at 513.66 meters (1,685 ft 3 in) in the Sierra de Carapé mountain range. To the southwest is the Río de la Plata, the estuary of the Uruguay River, which forms the western border, and the Paraná River, that does not run through Uruguay itself.