Miyao Castle (宮尾城 miyao-jō) was a fortification built on the island of Itsukushima (also known as Miyajima) during the Sengoku Period in Japan. Although referred to as a Japanese castle, it did not have a donjon (tenshu) or serve as the residence of a land-holding noble, and therefore is probably more within the definition of a hill fort, rather than a true castle. Built by Mōri Motonari, Miyao Castle was part of a greater plan to bait and trap his enemy, Sue Harukata, which culminated in the Battle of Miyajima in 1555.