is a Japanese castle in Akashi, Hyōgo Prefecture, Japan. This castle was constructed by Ogasawara Tadazane as his own castle from 1617 to 1619 to watch over the western lords, by the order of Tokugawa Hidetada, on Mount Akamatsu. The castle was built in one year, which was a relatively short amount of time. This was done so quickly because as a result of a 1615 law mandating one castle per clan, many castles were dismantled and parts of some were used to construct Akashi Castle. Akashi castle underwent major repairs in 1739, and was demolished by the Meiji Government in 1874.