Located east before the entrance of the present-day Rengeji Temple, marks a stone monument with an inscription indicating the site of the castle ruins.
It is believed to have been a flat shaped square castle site with a 200 square meter plot of land. There is no indication when the castle was built however it was the epicenter of the Hachisuka clan.
No remains appear to remain today, but the area around the inner sanctuary feels like the remains of a single-walled castle. This is said to be the birthplace of Hachisuka Koroku Masakatsu (1526-1586).