Caption:
Cell block A. A-Block was never modernized, so retained its flat strap-iron bars, key locks and spiral staircases from the original military prison. The Alcatraz Federal Penitentiary was a maximum security federal prison on Alcatraz Island, 1.25 miles off the coast of San Francisco, California, United States, which operated from August 11, 1934, until March 21, 1963. Historic American Buildings Survey, Jet Lowe, 1986 (cropped and cleaned).