Batam is the largest city in the province of Riau Islands, Indonesia. The city administrative area covers three main islands of Batam, Rempang, and Galang (collectively called Barelang), as well as Bulang to the west and several smaller islands. Batam Island is the core urban and industrial zone, while both Rempang Island and Galang Island maintain their rural character and low-density population; they are connected to Batam Island by short bridges. Bulang Island and the islands to its north forming Belakang Padang District lie to the west of Batam Island but are also administratively within the city. Batam is an industrial boomtown, an emerging transport hub, and part of a free trade zone in the Indonesia–Malaysia–Singapore Growth Triangle, located 20 km (12 mi) off Singapore's south coast.