What are castles made of?
Usually from stone, but early motte and baily forts were made of wood. Some fortresses in Eastern Europe were made of brick, since stone is scarce there.
This depends on what type of castle your referring to. In the Norman times, there were two different types of castles built. There were Motte and Bailey castles and Stone keep castles (Stone castles). The Motte and Bailey castles were made out of wood and the Stone keep castles were made out of stone (obviously).