Medieval Castles Medieval Castles were huge protection camps made to protect the king. They had every kind of defense known to medieval man. From murder holes, to arrow-loops, a castle had it. Medieval castles were usually built on a high rocky cliff located by water. Castle locations were very hard to find and sometimes months were spent looking for one. A moat was built around the castle and was usually filled with sewage and bathroom “goodies.” All these things played an important part in keeping the castle strong and ready to fight. A couple other defenses the castle had were murder holes; soldiers would dump many things on