Bougainville Island is the main island of the Autonomous Region of Bougainville of Papua New Guinea. This region is also known as Bougainville Province or the North Solomons. Its land area is 9,300 km². The population of the province is 175,160 (2000 census), which includes the adjacent island of Buka and assorted outlying islands including the Carterets. Mount Balbi at 2,700m is the highest point. Although Bougainville Island is geographically part of the Solomon Islands archipelago, the state of Solomon Islands is not a part of Papua New Guinea.