Chikaraishi (力石, chikaraishi, lit. "strength stones") (also hakari-ishi (秤石, "weighing stones") or bijuru (Okinawan) are heavy rocks used at least since the 8th century CE in Japan to develop or demonstrate physical strength. Commonly found within Shinto shrines, they were used for competition, divination, physical fitness and entertainment; some famous examples have also become tourist attractions, and many have been recognised as Important Cultural Assets by the Japanese Government.