Castle walls are strong, thick structures built to protect a castle from attacks. They are usually made of stone and can be several feet high. The walls often have towers and battlements, which provide a vantage point for defenders to spot enemies and defend the castle. In addition to their defensive purpose, castle walls also symbolize power and authority. Many castles, like those found in Europe, were built during the Middle Ages to showcase the strength of the ruling nobility. These walls often surrounded a courtyard, where various activities took place, including markets and gatherings.