Brazil is the largest country in South America and the only Portuguese-speaking country in the Americas. It is the world’s fifth largest country, both by geographical area and by population. Bounded by the Atlantic Ocean on the east, Brazil has a coastline of over 7,491 kilometers (4,655 mi). It is bordered on the north by Venezuela, Guyana, Suriname and the French overseas department of French Guiana; on the northwest by Colombia; on the west by Bolivia and Peru; on the southwest by Argentina and Paraguay and on the south by Uruguay. Numerous archipelagos are part of the Brazilian territory, such as Fernando de Noronha, Rocas Atoll, Saint Peter and Paul Rocks, and Trindade and Martim Vaz. Brazil was a colony of Portugal from the landing of Pedro Alvares Cabral in 1500 until its independence in 1822. Initially independent as the Brazilian Empire, the country has been a republic since 1889, although the bicameral legislature, now called Congress, dates back to 1824, when the first constitution was ratified. Its current Constitution defines Brazil as a Federal Republic. The Federation is formed by the union of the Federal District, the 26 States, and the 5,564 Municipalities. Brazil is the world’s eighth largest economy by nominal GDP and the ninth largest by purchasing power parity. Economic reforms have given the country new international recognition. Brazil is a founding member of the United Nations, the G20, Mercosul and the Union of South American Nations, and is one of the BRIC Countries. Brazil is also home to a diversity of wildlife, natural environments, and extensive natural resources in a variety of protected habitats.