A Crusader castle refers to the fortifications built by European Christians during the Crusades, a series of religious wars from the 11th to the 13th centuries. These castles were strategically located in the Holy Land to protect territories and serve as military strongholds. They often featured thick stone walls, towers, and moats to defend against attacks. Many Crusader castles, such as Krak des Chevaliers in Syria and Montfort Castle in Israel, showcase impressive medieval architecture. They were not only military bases but also served as administrative centers and living quarters for knights and their families. Today, these castles are important historical sites that attract tourists and historians alike.