The Alcatraz Island was originally used as a fort during the middle 19th century but as its defenses became obsolete, the army decommissioned it as a fortification. Then it became a prison just some years later. Being a home to infamous inmates like Al Capone and Robert Stroud, Alcatraz became the most famous prison having been a subject in films like The Escape from Alcatraz with Clint Eastwood. Today Alcatraz Island is a national park, visited by thousands of visitors every year.