The Sangu River is a river in Myanmar and Bangladesh. Its source is in the North Arakan Hills of Myanmar, located at 21°13´N 92°37´E. The Arakan Hills form the boundary between Arakan and the Chittagong Hill Tracts. It follows a northerly circuitous course in the hill tracts and then enters Bangladesh near Remaikri, Thanchi Upazila, Bandarban District, from the east. It flows north through Thanchi, Rowangchhari and Bandarban Sadar Upazilas of Bandarban district. It then flows west through Satkania and Banshkhali Upazilas in Chittagong district and flows into the Bay of Bengal near Chittagong, at 22°6´N 91°51´E, or about 16.09 kilometres (10.00 mi) south of the mouth of the Karnafuli River. The length of the river is 270 kilometres (170 mi) of which 173 kilometres (107 mi) are located within Bangladesh.