|Highest elevation||Fogatia Hill
287 inhabitants / km²
The area of the island is about 1.52 km². Almost all of the island's 436 inhabitants live in the only place Aunuʻu on the west coast.
The island is only separated from its large neighboring island of Tutuila by an approximately 1 km wide waterway and is located opposite the village of Utumea. The closest point is Matuli Point a little east of Utumea.
The east is formed almost exclusively by the caldera of an extinct volcano. The two peaks of the island are on the crater rim. Pofala Hill at 75 meters to the north is the location of the lighthouse . In the south lies Fogatia Hill, which according to some sources is even higher than Pofala Hill.
Large amounts of fresh water have accumulated inside the volcanic crater, creating a unique flora and fauna. Because of the high diversity of plants and animals in the Faimulivai Marsh in the center of the caldera, the area of the caldera was placed under nature protection.
Administratively, Aunuʻu is one of the six villages in SaʻOle County , which is part of the Eastern District of American Samoa.