Tateyama Historical Park (Iwayado Castle Honmaru Ruins)
The castle ruins of a powerful family that ruled this region since ancient times. It is said that Fujiwara Tsunekiyo and his son Kiyohira used it as a fortress in the late Heian period. In addition, an octagonal hall building, Nisei-in (Buddha statue preservation), was built as a facility to honor the achievements of the father and son Tsunekiyo and Kiyohira. You can enjoy the seasonal scenery with cherry blossoms, hydrangeas, and maple trees.
Nisei-in is usually closed. Open twice a year (May and August).