The girls did great and slept the whole time inside the castle. The views were great. And we met up with friends. All in all, it was a very good day trip.
Burg Hohenzollern is a little less than an hour South of Stuttgart. We went for the Falcon and Knight Day. The "festival" part turned out to be a bird show and a knight on horseback, not really the medieval fair type of event. But it did mean that the castle was open to unguided viewing, always a plus for us. Like most castles in Germany, you can only see the inside with a paid tour, usually in German. Either way, the views are fantastic, and it's a close, un-mobbed castle castle.