The island is the eroded remnant of a hotspot shield volcano with a caldera complex or collapse feature (Liu Bench) on the south face. The summit of the island, called Lata Mountain, is at an elevation of , making it the highest point in American Samoa. The last known volcanic eruption in the Manuʻa Islands was in 1866, on the submarine ridge that extends west-northwest towards nearby Ofu-Olosega.