The island is 29.7 km long and 11.8 km wide.: Its area is . It is one of the three sandy eastern islands (Sal, Boa Vista and Maio) of the archipelago, with white sandy beaches. The island is fairly flat; its highest point is Monte Grande, at 406 m elevation.: The uninhabited islet Ilhéu Rabo de Junco lies near the west coast of Sal. Saline marshes can be found in the Pedra de Lume crater and north of Santa Maria.