Caja de Muertos(Coffin Island) is an uninhabited island off the southern coast of Puerto Rico, near Ponce, Puerto Rico. Native turtles can be found on the island which is protected by the Caja de Muertos natural reserve. It is believed the island got its name because it resembles someone lying down when seen from southern Puerto Rico.
Caja de Muertos is 2.75 km long northeast-southwest, and up to 860 meters wide with a dry forest. The island has a lighthouse, Caja de Muertos Light and four beaches: Playa Pelicano, Playa Larga, Playa Chica, and Playa Blanca. Hikers and beachgoers are often seen in the island.
Caja de Muertos can be reached by ferry from the La Guancha Boardwalk sector of Ponce Playa.