Its ruins have been protected as an Okayama City Designated Historic Site.

[1] The castle was bulit by Nakayama Nobutada in the Tenbun period (1532–1555).

[2] In 1559, Ukita Naoie killed Nakayama Nobumasa by order of Uragami Munekage.

[3] Then Naoie moved Ukita clan's main bastion from Shinjōyama castle.

[3][6][1] Soon after the Honnō-ji Incident, Hashiba Hideyoshi stopped and stayed in the castle on his way back to Kyoto to fight Akechi Mitsuhide's army.