From the exercise yard of the former maximum security prison, I look beyond barbed wire-topped walls to San Francisco's Golden Gate Bridge, a sight that must have reminded inmates of the world they'd lost. So, did anyone escape? Not according to the warden in the movie Escape From Alcatraz, who asserted: 'No one has ever escaped from Alcatraz. And no one ever will.' Despite the boast, three men made it off the island in 1962 and were never found, officialdom insisting they'd drowned. But in 2003, Jamie Hyneman and Adam Savage of the television show MythBusters constructed an inflatable raft from rubber raincoats, carried plywood paddles as the escapees did and, on the outgoing tide, made it from Alcatraz to the north tower of the Golden Gate Bridge, proving that escape was possible. To tour Alcatraz, head to Pier 33 at Fisherman's Wharf for the Alcatraz Cruises vessel. Collect the Cellhouse Audio Tour to hear the voices of guards and inmates who lived there. After disembarking and listening to a ranger's introductory talk, visitors head uphill past the watch-tower. In the main cell block the imagination runs riot and footsteps still seem to echo. There's a feeling that the heavy doors may clang shut at any moment. In 1934 this former military prison passed to the control of the US Justice Department and was redesigned to cater for America's worst gangsters in the post-Depression era. Foremost among them was Al Capone, who occupied cell 181 (left) on the Rock, as Alcatraz was known to inmates. Other famous prisoners included bank robber George 'Machine Gun' Kelly and Robert Stroud, known as the Birdman of Alcatraz and remembered as mild-mannered, thanks to Burt Lancaster. In fact, Stroud was violent and was denied access to his birds at Alcatraz. The Cellhouse Tour includes the gun gallery, where guards watched for signs of trouble through a hole made for a rifle barrel. Learn how the Birdman spent only 90 days with the general prison population, six years in D Block and 11 years in the prison hospital, the new warden figuring that a private room there was the best way to keep him isolated. You can see the solitary confinement cells where prisoners had to while away the time. US Attorney-General Robert Kennedy closed the prison on March 21, 1963. The isolation that suited a maximum-security penitentiary meant that the cost of much-needed repairs was prohibitive.