Location: San Francisco
Year opened: 1934 (closed 1963)
Inmate population: 336
Facts: During its 29 year history Alcatraz incarcerated 1,576 prisoners-- from Robert Stroud, "The Birdman of Alcatraz," to Alvin Karpis, the first public enemy No. 1. There were 14 escape attempts from "The Rock." The prison closed in 1963 because it was too costly to operate-- nearly 1 million gallons of water were shipped to the island each week. Alcatraz is now a national park site-- it has nearly 1 million visitors a year.