The mountainous island measures east-west, and is up to wide. With an area of, it is the second largest island of the archipelago, after Vanatinai. The higher parts of the island are almost constantly cloud-capped during the southeast monsoon. The mountain ridges form short, narrow crests, with occasional peaks; their outline is smooth, and the ridges are covered with vegetation. Most of the shoreline is either bordered by mangroves, with occasional sandy beaches, or covered with jungle. From the bluff to the island's north point, very steep hills slope down to the shore. Between the north point of the island and Cape Deliverance are some well-wooded valleys. The south side of the island consists of numerous points and bays, with steep hill ridges descending to the sea from the high mountain range above. ;Mount Rossel The highest elevation is Mount Rossel, near the eastern end of the island, which rises. This precipitous peak has steep ridges extending to the north and west, but it descends in more gentle slopes southeast to Cape Deliverance, the eastern end of the island. The southwest ridge has two conspicuous peaks each high. The eastern peak, Mount Mo, is flat-topped. The western peak is conical. At the western end of the island is a conspicuous conical peak high. ;Reef The fringing coral reef encloses the large Rossel Lagoon in the west and a smaller lagoon one in the east. Rossel Lagoon extends almost from the northwestern point of the island to Rossel Passage at the western end of the fringing reef. The barrier reef encircling this lagoon is narrow and has four passages through it west of the island. The barrier reef on the south side of the island is unbroken east of Rossel Passage. General depths in the lagoon range from, but numerous scattered shoals lie in it. Few of these shoals dry and the larger ones are usually awash. Since the water is so clear the shoals can usually be distinguished in good light.
History
Rossel Island was first sighted and charted by Europeans on 14 July 1606 by the Spanish expedition of Luís Vaez de Torres. Together with Tagula Island it was charted as Tierra de San Buenaventura as it was first sighted on the feast of that saint.
Flora and fauna
Rossel Island is thickly wooded and nearly the whole south coast is a dense forest. Grassy patches are occasional.
Demographics
In 2014, the population was 5,553, spread across 31 villages. The main village is Jinjo, on the east coast. The indigenous people speak the Yélî Dnye language, whose relation to other languages remains uncertain.
