Trim Castle, Ireland: "Another fascinating defense measure inside the keep was the way the stairwells were made. They would have a clockwise rotation so defenders of the keep could easily use their right hand sword hand. Attackers trying to go up the stairs would have their sword hand agains the inner wall. That made it difficult for them to swing their swords. And, these stairwells would be trick in that the height and the depth of the steps would vary...."