When the basement of Dublin Castle flooded during a recent hurricane, inspections of the building's foundation revealed this old part of the Viking wall. The only unprotected part of Dublin Castle was this stairway, which had a few secrets. First, it was surrounded by a natural moat, the River Poddle, which was little more than an open sewer. The steps are too narrow for a whole foot and very steep. It would be very difficult to carry any weapons with you up those stairs. If you made it that far, you’d find that the door opens out, not in, so the defenders could push you out, right back into the River Poddle.