The country comprises about 600 small islands and has some 5,150 km of coastline; only 13 per cent of people live in urban areas, the lowest proportion in the Commonwealth.
Papua New Guinea has more than 800 indigenous languages, thought to be more than any other country in the world.
The Independent State of Papua New Guinea in the South Pacific shares a land-border with Indonesia; its other near neighbours are Australia to the south and Solomon Islands to the east.
Papua New Guinea includes the eastern half of the world’s second biggest island, New Guinea, bordering the Indonesian province of Irian Jaya to the west. The rest of the country is made up of about 600 small islands, the chief of which are the Bismarck Archipelago, the Trobriands, the Louisiade Archipelago, the D’Entrecasteaux Islands, and some of the islands in the Solomons group, including Bougainville.
The country comprises 22 provinces including the National Capital District (greater Port Moresby) and the Autonomous Region of Bougainville.
Port Moresby (capital, pop. 364,125 in 2011), Lae (Morobe, 155,000), Arawa (on Bougainville, 38,600), Mount Hagen (Western Highlands, 29,176), Madang (Madang, 29,100), Wewak (East Sepik, 27,031), Goroka (Eastern Highlands, 16,700), Kimbe (on New Britain, 16,004), Daru (Fly River, 14,373), Vanimo (Sandaun, 13,357), Alotau (Milne Bay, 12,628), Kundiawa (Simbu, 11,455), Popondetta (Oro, 10,200), Kavieng (on New Ireland, 9,900), Bulolo (Morobe, 9,850), Mendi (Southern Highlands, 8,500), Kokopo (on New Britain, 6,300), Wau (Morobe, 4,950) and Rabaul (on New Britain, 3,945).
Construction of roads is hampered by the rugged mountainous environment and the total national road network extends to 19,600 km, 3.5 per cent paved. Port Moresby is perhaps the only capital city that is not linked by road with the rest of the country. There is no railway.
Principal ports are Alotau (on the southern tip of New Guinea), Port Moresby (on the south coast), and Lae, Madang and Wewak (on the north coast), Rabaul (in New Britain), Kieta (Bougainville) and Momote (Manus Island). As there are relatively few roads, river transport is important, for both freight and passengers, and particularly on the River Sepik.
The international airport is Port Moresby at Jackson Field, 11 km from the city. Domestic air services run to all centres of population and industry.
Papua New Guinea is a member of the African, Caribbean and Pacific Group of States, Asia–Pacific Economic Cooperation, Non- Aligned Movement, Pacific Community, Pacific Islands Forum, United Nations and World Trade Organization.
The centre of the main island is a rugged mountainous ridge, with several wide valleys, and foothills north and south. The rivers Sepik and Ramu drain the foothills to the north, and the rivers Fly, Kikori and Purari those in the south. Though fast-flowing, many rivers are navigable. There are active volcanoes along the north coast, and some volcanoes and warm pools in the south-east islands.
Tropical monsoon type, hot and humid all year, though somewhat cooler in the highlands. Rainfall is chiefly from December to March. High mountains receive occasional frost, even snow.
The most significant environmental issues are rainforest deforestation as a result of growing commercial demand for tropical timber; pollution from mining projects; and severe drought.
Rich and very varied: five kinds of lowland, and 13 kinds of mountain rainforest, five kinds of palm and swamp forests, three differing mangrove forests, and the world’s greatest variety of orchid species. Forest covers 63 per cent of the land area, having declined at 0.5 per cent p.a. 1990–2010. Arable land comprises one per cent and permanent cropland two per cent of the total land area.
There are no large mammals but a rich variety of marsupials, reptiles and some 700 species of birds, including 38 species of the spectacular bird of paradise and related bower-birds. Papua New Guinea also has many thousands of unusual species of insect including the world’s largest species of butterfly, the Queen Alexandra birdwing, and brilliant green scarab beetles which are used for jewellery. Indigenous marsupials include tree kangaroos, wallabies, bandicoots, cuscus and spiny anteaters. Dugongs live in the waters near the coast. The creation of national parks was a slow process, the government being reluctant to interfere with traditional methods of land tenure, but there are now four national parks, and protection measures have been introduced, banning the export of birds of paradise. Some 39 mammal species and 32 bird species are thought to be endangered (2014).