coral formations in the Solomon Sea of the southwestern Pacific, Papua New Guinea, 90 miles (145 km) north of the southeasternmost extension of the island of New Guinea. The low-lying group of 28 islands, all of coralline limestone and many fringed by coral reefs, comprises four larger islands, Kiriwina (Trobriand), Kaileuna, Vakuta, and Kitava, and several islets, with a total land area of about 170 square miles (440 square km). The largest, Kiriwina, is a raised atoll 30 miles (48 km) by 3–10 miles (5–16 km). Covered largely with swamp, it rises to 100 feet (30 metres) at a central ridge. The island, the chief settlement of which is Losuia, was an air and naval base for the Allies in 1943. In drier areas the Trobrianders (Trobriander) produce yams for export to other islands.