Kinojo Castle, or Demon Castle, is an ancient mountain fort linked in local legend to the demon Ura from the Momotaro story. Archaeology places the fort between the 4th and 7th centuries, making it one of Japan's oldest castle sites.
Today visitors can see earthworks, wall remains, and a reconstructed west gate. A free visitor center explains the site with models and artifacts, and the ridge setting gives broad views over the Kibi plain.