Built by Saigo Tsugiyori, a daimyo of Mikawa, and lived in 70 years later by Matsudaira Kiyoyasu, the grandfather of Tokugawa Ieyasu. After Hirotada, the father of Ieyasu was killed, it was put under the power of the Imagawa. After the Battle of Okehazama, Ieyasu once again entered the castle, conquered Mikawa and set this place as the base for his national unification. Now this castle is familiar to citizens as a Historical records museum. On south side of Okazaki park, along the Otsu river levee, there are wisterias blooming from the end of April to early May. The Gomangoku Wisteria Festival is held here every year.