As a connesour of American national parks, I went to see the Peaks National Park, in the north midlands of England. I was impressed with the perfect combination of castles and sheep (this one is Peveril Castle with the sheep Simon, Betsy, Snowball . . . ).
We see from this scale model below that the engineers had quite a creative plan to throw off enemy attackers. They brilliantly put the moat inside the castle. I haven't yet understood why it is brilliant to do this but I'm sure that it is.
I was about to fill my canteen here, but then I saw the sign. Not drinking water, phew! Shame though, it looked delicious.