The island is located approximately 38 kilometres (24 mi) south of the Western Province of Papua New Guinea. Turnagain is 7.5 kilometres (4.7 mi) in length and up to 2.2 kilometres (1.4 mi) wide. Its area of 11.98 square kilometres (4.63 sq mi) is heavily wooded. It is uninhabited and is the shape of an elongated teardrop.