Roncador Bank is a mostly-submerged atoll with several sandy cays. It lies in the west Caribbean Sea off the coast of Central America. Originally claimed by the United States under the Guano Islands Act of 1856, the atoll was ceded by the United States to Colombia on September 17, 1981, as the result of a treaty signed in 1972. It is about 15 by 6 kilometers in size, with an area of 65 km² composed mostly of lagoon. In the northern area lies Roncador Cay. There are several dilapidated houses on it built by American troops during the Cuban Missile Crisis. An old disused lighthouse is at its northern end. A new lighthouse has been operating since 1977.