Drawbridge
type of movable bridge
A drawbridge is a bridge that can be moved in order to stop or allow passage across it. They were often built as part of medieval castles which had moats.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Lagos48.jpg/220px-Lagos48.jpg)
Modern drawbridges are often built across large, busy waterways. They can be lifted to allow large ships to pass or lowered to allow land vehicles or pedestrians to cross.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/df/MovableBridge_roll.gif/220px-MovableBridge_roll.gif)