Papua New Guinea, independent nation lying east of Indonesia and north of Australia in the south-western Pacific Ocean. The eastern half of the island of New Guinea, called the mainland, accounts for more than 80 per cent of the total land area of 462,840 sq km (178,704 sq mi). The most important of Papua New Guinea's many island groups are the Bismarck Archipelago, the Louisiade Archipelago, the Trobriand Islands, the D'Entrecasteaux Islands, and Woodlark Island; other nearby islands include Bougainville and Buka.