Murder holes are openings in the ceilings of castle gateways or passageways, designed for defense. They allowed defenders to drop projectiles, such as stones or boiling liquids, onto attackers trying to breach the entrance. This strategic feature helped protect the castle from invaders. Typically found in medieval castles, murder holes were part of a larger defensive system that included features like moats, drawbridges, and portcullises. Their design aimed to create a formidable barrier against siege tactics, enhancing the overall security of the fortress.