It's one of the must-see tourist destinations in San Francisco – just as the Golden Gate Bridge, Fisherman’s Wharf, Lombard Street, Ghiradelli Square and the cable cars are. It’s Alcatraz Island, now part of the Golden Gate National Recreation Area.

Alcatraz served as a federal prison for 30 years and the self-guided tours are fascinating.  It's pretty rugged with a lot of steep climbs, but they have small trolleys to get you from the bottom to the top if you need it.

At one time it housed over 200 maximum security inmates. It’s a 12-acre island, a mile and a half from Fisherman’s Wharf. The only way you can reach it is by boat and it was famous for how miserable it was to stay there. Not only the way prisoners were treated but the cold, damp conditions.

Sometimes known simply as “The Rock”, nearly complete silence was mandatory. It featured some of the most advanced security features of its time. Some of the first metal detectors were used at Alcatraz. Because the currents that run around it are so strong and water so cold, even if a prisoner was able to somehow escape the walls, barbed wire and the armed guards in the lookout towers the chances of someone surviving in the water were pretty slim.

The name Alcatraz is taken from a Spanish word Alcatraces meaning Pelicans because of the all the birds that lived there. The first lighthouse in California was on Alcatraz. It was a Civil War fort and then later a military prison.

It was closed and its last prisoners were transferred elsewhere 50 years ago today in 1963.