If you're an early riser, the castle is a great place to visit in the morning before everything else is open. I had it all to myself, because I went super-early in the morning. It was cool to have my own, private changing of the guards ceremony. Also, it took me several hours just to walk around and see all of the architecture from the outside. I have to admit, I think it would also be cool to see stuff from the inside, but at that point, I would have needed a whole day.
This review is the subjective opinion of a TravelPod member and not of TravelPod.com.