This place is a must if you're headed to San Francisco. Make sure to bring a jacket since it can be a bit chilly on island, at least it was when we went. Everything is very well organized and you can visit the prison with guided-tour headphones (in many languages) and explore at your own pace and take pictures. There's a boat back to the mainland every hour or so. You're taught about life at the prison, you see where inmates arrived, the cells where they spoke with relatives, where the guards lived, the hsitory of some of the escape attempts, and the reasons the prison was eventually closed. Al Capone was the most famous and well-known prisoner there.