Vieques has a terrain of rolling hills, with a central ridge running east–west. The highest point is Monte Pirata ("Pirate Mount") at . Geologically the island is composed of a mixture of volcanic bedrock, sedimentary rocks such as limestone and sandstone, and alluvial deposits of gravel, sand, silt, and clay. There are no permanent rivers or streams. Much former agricultural land has been reclaimed by nature due to prolonged disuse, and, apart from some small-scale farming in the central region, the island is largely covered by brush and subtropical dry forest. Around the coast lie palm-fringed sandy beaches interspersed with lagoons, mangrove swamps, salt flats and coral reefs.