San Francisco Bay is the artificial and flat Treasure Island, site of the 1939 Golden Gate International Exposition. From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the Bay is Alcatraz, the site of the famous federal penitentiary. The federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site. Despite its name, Mare Island in the northern part of the bay is a peninsula rather than an island. San Francisco Bay is thought to represent a down-warping of the Earth's crust between
Alcatraz Federal Penitentiary Robert Franklin Stroud (the "Birdman of Alcatraz"), George "Machine Gun" Kelly, Bumpy Johnson, Rafael Cancel Miranda, Mickey Cohen, Arthur R. "Doc" Barker, Whitey Bulger, and Alvin "Creepy" Karpis (who served more time at Alcatraz than any other inmate). It also provided housing for the Bureau of Prisons' staff and their families. A total of 36 prisoners made 14 escape attempts during the 29 years of the prison's existence, the most notable of which were the violent escape attempt of May 1946 known as the "Battle of Alcatraz", and the arguably successful "Escape from Alcatraz" by Frank Morris, John Anglin, and