All but one of the towns of New Guinea are located on or immediately adjacent to the seacoast, the gold-mining center of Wau in the eastern interior being the sole exception. Chief ports are Port Moresby on the eastern shores of the Gulf of Papua, Lae on the western shores of Huon Gulf, Finschhafen on the Huon Peninsula to the north of Lae, Madang and Alexishafen on the north coast west of the Huon Peninsula, Aitape and Hollandia on the north-central coast, and Merauke on the south-central coast. (Strictly wartime developments, such as Nadzab and Gusap in the Markham Valley, Sausapor on the northern shores of the Vogelkop, Milne Bay in the extreme southeast, and Dobodura between Milne Bay and Lae in the northeast, are not included for the reason that they ceased to exist as towns after military operations passed beyond New Guinea. Nor is it certain that such towns as Buna and Salamaua on the northeast coast, which were obliterated by bombing during the Second World War, will be reconstructed, for easier and more dependable access to the interior is now provided via Lae to the west.)
The Bismarck Archipelago consists of two fairly large, mountainous islands, New Britain and New Ireland, and a considerable number of smaller islands and islets that together with their larger neighbors ring the Bismarck Sea on the south, east, and northeast. Their combined area is about 19,200 square miles, most of which is accounted for by New Britain, the largest in the group, and by New Ireland, the second largest. These two islands are long, relatively narrow, and curve within a few miles of each other at their eastern extremities. Off the northern shore of New Britain are several isolated volcanic cones, roughly circular in outline; off northwestern New Ireland lie a number of low, nearly flat, irregularly shaped coral islands and reefs extending westward toward the Admiralty group. Elsewhere a scattering of small islands, some volcanic and some primarily marine in origin, complete the picture.