It is located in the far northern part of the Mariana arc of volcanic islands, situated 101 km northwest of Agrihan and 37 km southeast of the Maug Islands; the island of Pagan lies 175 km to the southwest. It is a stratovolcano, 857m at the tallest point, and has a land area of 7.31 km² (2.82 sq mi). Most coastlines are rocky or clifflike. There are a number of deep ravines breaking up the slopes. Administratively it is a part of the Northern Islands Municipality.
The island is heavily vegetated with coconut palm plantations and broadleaf forests. The ravines are also heavily vegetated with other woody species. The island is uninhabited.
