Isla de la Juventud, called the Isle of Pines until the mid-1970s, island, southwestern Cuba, separated from the main island by the Gulf of Batabanó. The economy of Isla de la Juventud (Spanish for “Island of Youth”) is based on tourism, fishing, and agriculture. Its administrative center is Nueva Gerona. The island, first visited by Christopher Columbus in 1494, was subsequently inhabited by pirates and escaped slaves. Spain relinquished the island after the Spanish-American War (1898), and the U.S. and Cuba both claimed it until a treaty between the two countries, ratified in 1925, confirmed Cuban sovereignty. In the early 1950s Fidel Castro, later the leader of Cuba, was incarcerated in a large prison near Nueva Gerona. The prison is now a national monument and museum. Population (1989 estimate) 70,900.