It is a major port for ferry crossings to Tawau in Sabah state, Malaysia.The northern part lies in Malaysia and the southern half within Indonesia.The Indonesian portion has an area of 246.61 km2 and had a population of 47,571 at the 2020 census,[3] comprising five of the regency's districts.The Apokayan region (i.e. all the first five districts listed above) comprises the entire western section of the Regency, separated from Malaysia by the meandering Kayan River.It consists of 4 kelurahan (Mansapa, Nunukan Selatan, Selisun and Tanjung Harapan).