Guyana is a republic in South America, bordered by Venezuela to the west, Suriname to the east, Brazil to the south, and the Atlantic Ocean to the north. First human settlement of the region dates to 35,000 years ago. At the time of Christopher Columbus' voyage in 1498, Guyana was dominated by Arawak and Carib tribes. The Dutch established colonies in Essequibo (1616), Berbice (1627), and Demerara (1752), named after the three main rivers which flow through Guyana. The British gained control of the three colonies following a treaty in 1814, and was renamed British Guiana in 1831. The establishment of the boundaries of British Guiana triggered a border dispute with Venezuela, which was settled by international arbitration in 1899, but remains a source of political friction. In 1966, Guyana was granted independence and in 1970 became a republic. The capital and largest city is Georgetown. The estimated population of Guyana in 2013 was 739,903.