Sunda Islands, group of islands extending from theMalay Peninsula to the Moluccas southeast of the Asiatic mainland towardNew Guinea. They include the Greater Sundas (Sumatra,Java,Borneo,Celebes, andadjacent smaller islands) and the Lesser Sundas (Bali,Lombok,Sumbawa,Sumba, andFlores,Timor, Alor, and adjacent smaller islands). With the exception of Borneo, easternSumatra, and nearby areas, they belong to the zone of island arcs and submarine ridges, lying betweenAsia and Australia, which are geologically unstable and volcanically active. Bounded by theIndian Ocean on the south and west and by theStrait of Malacca, theSouth China Sea, and theCelebes Sea on the north and east, the islands surround the Java, Flores, and Savu seas. The islands include most of the land area ofIndonesia, with only northern and northwestern Borneo not under Indonesian political control. Malaysiancultures and languages predominate in the area.