The small islands of Hunga Tonga (upper left) and Hunga Ha'apai (left) cap a large seamount located about 30 km SSE of Falcon Island. The two linear andesitic islands are about 2 km long. They have inward-facing cliffs that represent the western and northern remnants of a the rim of a largely submarine caldera lying east and south of the islands. A rocky shoal is visible 3.2 km SE of Hunga Ha'apai and 3 km south of Hunga Tonga and marks the most prominent historically active vent.
Aerial photo by Tonga Ministry of Lands, Survey, and Natural Resources, 1991 (published in Taylor and Ewart, 1997).