Visited Alcatraz. The old prison site is now a national park. There are so many people wanting to go that you really need to book well in advance. Otherwise, you won't get in.

I'm not sure if I just got lucky or if this always happens, but at the exit of the main exhibition, there was a former Alcatraz inmate (wearing a hat) who had written a book about his time there. He was signing copies for customers.