A piece of wood connected to the castle by iron. When raised the enemy would have to either fill in the moat or tunnel underground and then up into the castle.
It is movable bridge. It is used as an entrance to a castle surrounded by a moat. Go to this link to see it.. http://en.wikipedia.org/wiki/DrawbridgeDon't worry there is no virus or anything! Hope I...
The moat was a defensive feature of a castle. the drawbridge was to facilitate crossing the moat, that enabled it to be withdrawn at a moment's notice.