1. Castles were built to keep out animals and invaders
2. The first proper castels were built in england in the roman conquest in 1066
3. The castels were to big and we dont have invades attacking us
4.The drawbridge is a moveable wooden bridge that keeps attackers away. It covers the moat
5.Castles were no longer needed as there was no threat from attackers .They became homes for the wealthy.
6.The drawbridge because it blocks the entry of the castle.
From TREE.