Mount Balbi, Dormant stratovolcano in Bougainville Island, Papua New Guinea

Mount Balbi is a dormant stratovolcano on Bougainville Island in Papua New Guinea and the highest point on the island at around 2,715 meters (about 8,900 feet). Five volcanic craters sit on its eastern side, and the largest of them holds a lake that formed inside the volcanic cone.

Mount Balbi is a Holocene stratovolcano, meaning its cone was built during the current geological epoch, though the sources give no specific formation date. No eruption has been recorded in historic time. Its summit is made of coalesced cones and lava domes, and five volcanic craters lie east of the summit.

The name Balbi is used for the whole volcanic massif, whose summit is a cluster of coalesced cones and lava domes rather than a single peak. Five craters lie east of the summit, and one holds a crater lake. Visitors who reach the top find a large solfatara field, with fumaroles steaming near the craters.

The summit is a gentle prominence at 05°54′09″S 154°59′28″E, so orientation on the crest is straightforward once you are there. The five craters lie east of the summit, one holding a crater lake, and fumaroles cluster near them. Balbi has not erupted in historic time, but the solfatara field and vents still release volcanic gases.

Near the summit, an active solfatara field sends volcanic gases up through the ground via a series of fumaroles. These steaming vents show that heat and geothermal energy are still moving beneath the surface despite the volcano's dormant state.