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Sometimes referred to as "The Rock," Alcatraz Island on San Francisco Bay in California served as a lighthouse, then a military fortification, and then a federal prison until 1972, when it became a national recreation area. Now the island is open to tours.
Fifty years ago this week, one of the most notorious prisons in the world slammed its cell doors for the last time. Alcatraz, The Rock, The forbidding island fortress in the middle of San Francisco Bay.
It was a federal penitentiary housing some of the system's most dangerous inmates for 29 years. People like Al Capone, Mickey Cohen, and of course, the Bird Man of Alcatraz.
Today, it's one of San Francisco's biggest tourist destinations, attracting more than a million visitors a year. Here to tell us a little more about the history of Alcatraz is John Martino, a former park ranger at Alcatraz and the author of the book, "Fortress Alcatraz."