Alcatraz Federal Penitentiary

United States Penitentiary, Alcatraz Island, also known simply as Alcatraz (English: , Spanish: [alkaˈtɾas] "the gannet") or The Rock, was a maximum security federal prison on Alcatraz Island, 1.25 miles (2.01 km) off the coast of San Francisco, California, United States. The site of a fort since the 1850s, the main prison building was built from 1910 to 1912 as a U.S. Army military prison.