Marksburg Castle was a favorite for us. The architecture is haphazard and charming. You turn a a corner and you have no idea if you'll go into another room, a hallway, a staircase (going up, then down) or a window that does not look outside because more castle was added on making the window redundant. Our favorite part was the privy right behind the king's chair in the dining room. Apparently they never shut the privy door during meals or BMs. Classy. The tour was in English and our guide was excellent. They have two planned English tours every day at noon and 4pm. The view was spectacular over the Rhine. And the best part - YOU CAN TAKE ALL THE PICTURES YOU WANT. Hot damn. We loved it all, including the torture chamber. I would visit again.