New Britain (Niu Briten) is the largest island in the Bismarck Archipelago, part of the Islands Region of Papua New Guinea. It is separated from New Guinea by a northwest corner of the Solomon Sea (or with an island hop of Umboi the Dampier and Vitiaz Straits) and from New Ireland by St. George's Channel. The main towns of New Britain are Rabaul/Kokopo and Kimbe. The island is roughly the size of Taiwan. While the island was part of German New Guinea, it was named Neupommern ("New Pomerania").
In common with most of the Bismarcks it was largely formed by volcanic processes, and has active volcanoes including Ulawun (highest volcano nationally), Langila, the Garbuna Group, the Sulu Range, and the volcanoes Tavurvur and Vulcan of the Rabaul caldera. A major eruption of Tavurvur in 1994 destroyed the East New Britain provincial capital of Rabaul. Most of the town still lies under metres of ash, and the capital has been moved to nearby Kokopo.
New Britain extends from 148°18'31" to 152°23'57" E longitude and from 4°08'25" to 6°18'31" S latitude. It is crescent-shaped, approximately along its southeastern coastline, and from wide, not including a small central peninsula. The air-line distance from west to east is . The island is the 38th largest in the world, with an area of .
Steep cliffs form some sections of the coastline; in others the mountains are further inland, and the coastal area is flat and bordered by coral reefs. The highest point, at , is the stratovolcano Mount Ulawun in the east. Most of the terrain is covered with tropical rainforest and several large rivers are fed by the high rainfall.
New Britain was largely formed by volcanic processes, and has active volcanoes including Ulawun, Langila, the Garbuna Group, the Sulu Range, and the volcanoes Tavurvur and Vulcan of the Rabaul caldera. A major eruption of Tavurvur in 1994 destroyed the East New Britain provincial capital of Rabaul. Most of the town still lies under metres of ash, and the capital has been moved to nearby Kokopo.