Guyana, officially the Co-operative Republic of Guyana, is a country on the northern mainland of South America. It is the only English speaking country in South America, and is historically and culturally part of the Anglophone-Caribbean. In addition it is one of the founding member countries of the Caribbean Community organization, (CARICOM). Guyana is bordered by the Atlantic Ocean to the north, Brazil to the south and southwest, Venezuela to the west, and Suriname to the east. With an area of 215,000 square kilometres (83,000 sq mi), Guyana is the third-smallest sovereign state on mainland South America after Uruguay and Suriname. The region known as "the Guianas" consists of the large shield landmass north of the Amazon River and east of the Orinoco River known as the "land of many waters". Major rivers in Guyana include the Essequibo, the Berbice, and the Demerara. Originally inhabited by many indigenous groups, Guyana was settled by the Dutch before coming under British control in the late 18th century. It was governed as British Guiana, with a mostly plantation-style economy until the 1950s. It gained independence in 1966, and officially became a republic within the Commonwealth of Nations in 1970. The legacy of British rule is reflected in the country's political administration and diverse population, which includes Indian, African, Amerindian, and multiracial groups. Guyana is the only South American nation in which English is the official language. The majority of the population, however, speak Guyanese Creole, an English-based creole language, as a first language. Guyana is considered part of the Anglophone Caribbean. CARICOM, of which Guyana is a member, is headquartered in Guyana's capital and largest city, Georgetown. In 2008, the country joined the Union of South American Nations as a founding member.