Ogimachi Castle Site
In the fifteenth and sixteenth centuries, the area now covered by the municipality of Shirakawa was controlled by the family of the warlord Uchigashima. The family seized these lands in 1465 and established their stronghold at Kaerigumo Castle, south of the village of Ogimachi. They built a series of hilltop forts along the Sho River to protect their domains from incursions by rival families.
One of these forts was Ogimachi Castle, which is thought to have consisted mainly of earthen walls, a dry moat, and embankments constructed along the ridge of the hill that overlooks Ogimachi on the river’s east side, some 60 meters above the village. The hill was the ideal site for a fortress; it was bounded by steep cliffs on three sides and provided an unimpeded view over the river and the main road through the valley, which any enemies approaching from the north would have been likely to use. Additionally, the presence of several springs in the vicinity meant there would be no shortage of fresh water.
The Uchigashima hired a samurai family named Yamashita to oversee the fort and the nearby villages. This position allowed the Yamashita to exercise significant influence over local life, including religious practice. As a result, many ancient places of worship in Shirakawa were converted into Hachiman shrines, which were dedicated to the guardian deity of the warrior class. The Yamashita also championed Jodo Shinshu (True Pure Land) Buddhism, the school that eventually became the dominant form of Buddhism throughout the Sho River valley.
Whether Ogimachi Castle was ever tested in battle is not known. In 1585, an earthquake seems to have destroyed Kaerigumo Castle, dealing a fatal blow to the Uchigashima family. Yamashita Ujikatsu (1568–1653), the last lord of Ogimachi, chose to leave Shirakawa and entered the service of Toyotomi Hideyoshi (1537–1598), the future de facto leader of Japan. The fortress fell into disuse, and now only the overgrown dry moat hints at the site’s former function.