A moat. Whether they really had crocodiles in the moat is a moot question.
A Mote
a moat
a moat
a moat
a moat
Another word for a deep ditch that is dug around a castle is a moat. You could call it a trench, or you could fill it full of water and call it a moat.
a moat
A moat
A water-filled trench around a castle is known as a "moat."
On Call of Duty: World at War to get under the water move to the bridge beside the castle and enter the water. When in the corner press the up button repeatedly until the player is transported to under the castle.
a moat
A dry or water filled ditch around a castle is called a moat. The water in the moat is supplied by a nearby river. The word moat should not be confused with the French term motte which described a mound or hillock upon which a fortification was constructed. Please see related links.