Aerial photo of the Buka Passage
Bougainville is an island in the wider region of Island Melanesia. It is politically part of Papua New Guinea, comprising (with Buka and a few smaller islands and atolls) Bougainville Province (formerly, North Solomons Province), even though it is geographically part of the Solomon Islands chain.
Bougainville is recovering from a decade-long secessionist with the national government of Papua New Guinea, which officially came to an end in 2000.