Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many small islands and islets in the Caribbean Sea. It has a territorial extension of 916,445 km². The continental territory is bordered on the north by the Caribbean Sea and the Atlantic Ocean, on the west by Colombia, Brazil on the south, Trinidad and Tobago to the north-east and on the east by Guyana. The Venezuelan government maintains a claim against Guyana to Guayana Esequiba, an area of 159,542 km². For its maritime areas, Venezuela exercises sovereignty over 71,295 km² of territorial waters, 22,224 km² in its contiguous zone, 471,507 km² of the Caribbean Sea and the Atlantic Ocean under the concept of exclusive economic zone, and 99,889 km² of continental shelf. This marine area borders those of 13 states. The capital and largest urban agglomeration is the city of Caracas. The country has extremely high biodiversity and is ranked seventh in the world's list of nations with the most number of species.