Alcatraz Prison was a famous prison located on Alcatraz Island in San Francisco Bay from 1933 to 1963. Some key facts about the prison include that it held over 600 cells and had Al Capone as its most famous prisoner. Escape from Alcatraz was virtually impossible due to its location over 1.4 miles from shore and small island size of only 0.0344 square miles. It was discovered in 1775 by Sir Francis Drake and later purchased and converted into a prison in the 1840s.