Simpson Harbour is a sheltered harbour of Blanche Bay, on the Gazelle Peninsula in the extreme north of New Britain. The harbour is named after Captain Cortland Simpson who was surveying the bay while in command of HMS Blanche in 1872. The former capital city of Rabaul is on its shores. The harbour is part of a huge flooded caldera, Rabaul caldera. The harbour is ringed by a number of volcanoes.