Alcatraz Island is an island located in the San Francisco Bay, 1.5 miles (2.4 km) offshore from San Francisco, California, United States.[1] Often referred to as "The Rock", the small island served as a lighthouse, a military fortification, a military prison, and a Federal Bureau of Prisons federal prison until 1963.[2] Later, in 1972, Alcatraz became a national recreation area and received landmarking designations in 1976 and 1986.