Head here if you're into history (there's a ton of...

Head here if you're into history (there's a ton of it), and if you take one of their tours (every half hour, I believe), a beefeater will be happy to tell you all about it. The stories are great, and once you're done with the tour, you can explore on your own (you can explore before too, but I recommend the tour). Great experience with lots to see and learn.