one of the northernmost islands of Tonga, in the southwestern Pacific Ocean. Of volcanic origin, the island has an area of 6 square miles (16 square km) and rises to 479 feet (146 metres). It is part of the Niuatoputapu, or Niuas, group of islands that also includes Niuafoʿou and Tafahi. The village of Hihifo, in the southwestern part of the island, is the administrative centre of the Niuas group. The island serves as a regular port of call for interisland shipping between Tonga and Samoa. A wharf at Falehau, on the north side of the island, offers anchorage for yachts; there is an airport at Mataʿaho in the southwest. Copra, limes, and breadfruit are produced. Area Niuas group, 27.7 square miles (71.7 square km). Pop. (2006 prelim.) Niuas group, 1,652.