From an engineering standpoint there is a good explanation why a castle would have a moat. Take a look at these neighborhoods in South Florida, notice all the lakes. read more
Many castles were protected by moats, but they have nothing to do with water. A moat is simply a ditch. It’d be fairly deep and fairly wide, not just the sort of gutter you’d see by the side of a country road to drain water. We’re talking the height of a person, more or less, and wider than that. read more