The Medieval Castle with a Moat of Boiling Water
The 14th-century castle of Château de Coucy, located in northern France, was once equipped with a moat of boiling water. According to historical records, the moat was filled with scalding hot water from a nearby river, heated by a network of pipes. This innovative defense mechanism was designed to deter attackers, but it also came at a high price: the castle's owners reportedly spent a significant portion of their budget on maintaining the hot water system.