Aya Castle was located in Aya-cho, Higashimorokata-gun Miyazaki Pref. It was built by the Aya clan during the Genko era (1331-1334) in the Kamakura period. Hosokawa Yoshikado, a retainer of Ashikaga Takauji was enfeoffed this area of Aya. Then his son Yoshito built the castle and announced himself Aya Yoshito. The Aya clan served for the Ito clan later and Aya Castle was counted as one of 48 Ito castles. In 1577, when the Shimazu clan defeated the Ito clan, the castle was given to one of the Shimazu clan’s retainers, Niiro Hisatoki. In 1615, the castle was dismantled as per the Ikkoku-ichijo (One Castle per One Province) order.
In 1985, according to the study of the historical evidence carried out by Japan Castle Foundation, Japan’s first reproduced castle that was typical to the early Warring States period was constructed. This wooden three-story castle was built by the local carpenters using the traditional carpentry techniques and the local zelkova wood. The castle is open to public as a history museum, where visitors can see the lives of Japanese warriors in the middle ages.