Castles are located around the world with many different styles.
Some castles are heavily fortified with some of the facets described here.
Others, in more peaceful climates, are not formidable at all, but meant to impress with wealth, rather than might. Usually a castle will have several walls for protection. Walls were often curved, rather than straight to hold up better against a battering ram. Drawbridge - a large door that opened vertically to lower over a moat. An outpost for eating and sleeping.