Sarawak is one of two Malaysian states on the island of Borneo. Located in northwest Borneo, Sarawak is bordered by the Malaysian state of Sabah to the northeast, Kalimantan, the Indonesian portion of Borneo, to the south, and the independent country of Brunei in the north. The capital city, Kuching, is the economic centre of the state and seat of the Sarawak state government. Other cities and towns in Sarawak include Miri, Sibu, and Bintulu. As of the 2015 census, the population of Sarawak was 2,636,000. Sarawak has an equatorial climate with tropical rainforests and abundant animal and plant species. It has several prominent cave systems at Gunung Mulu National Park. Rajang River is the longest river in Malaysia; Bakun Dam, one of the largest dams in Southeast Asia, is located on one of its tributaries, the Balui River. Mount Murud is the highest point in Sarawak.