It is 4.8 km by 2.4 km in size, with an area 10 km². It is of volcanic origin. It has two prominent peaks. The tallest peak, Bárcena, rises to a height of 332 metres (1,089 feet) near the southern part of the island. It forms a typical volcanic crater. It is located between the remains of two older craters, Herrera in the middle of the island and the Montículo Cinerítico ("Ash Heap") in the southwest. There is no permanent source of freshwater.