Located some 5 miles south of Ponce laid "Caja de Muertos", (coffin island). The island is approximately 2.75 km wide by 1.85 km long, with a total area of 202 hectares.

The existing vegetation is typical of a semi-arid atmosphere predominating the thorny shrubs and cactus.

The Caja de Muerto Lighthouse is a 19th century lighthouse. Restored by the Department of Natural Resources and houses a lookout and a museum.

The island has no permanent inhabitants.