Tsugawa Castle Ruins
Tsugawa Castle, commonly called Shiro Yama (Castle Mountain), was built at an altitude of 140m on the point of a mountain ridge that protrudes in the shape of a peninsula where the Agano and Tokonami rivers merge.
The east side reaches to Kirin Mountain, the highest peak with an altitude of 195m, along the horseback-like ridge and the remaining 3 sides are steep and sheer with exposed bedrock. The whole mountain was tailored into a firm fortress with many large and small compounds, which were enclosures made of earth and stones. Galleries sat next to these natural fortresses, vertical trenches were dug down at strategic points and stone walls were built, which was unusual for a mountain castle in the medieval period.
As for the origins of Tsugawa Castle, the Ashina clan, an Aizu guardian, probably had Morihiro Fujiwara, one of their kinsfolk, build it in 1252 in order to defend the west side, the Aizu domain. Morihito, one generation after Morihiro, took the family name of Kanagami, becoming a chief vassal family of the Ashina family and the lords of Tsugawa Castle for generations.
The Kanagami clan fell after Masamune Date defeated Moriharu Kanagami, the 15th castle lord, in battle in 1589. After that the Aizu feudal lord changed to Date, Gamo, Uesugi and Gamo in turn, and each lord appointed their chief vassal as the Tsugawa Castle lord.
After the Tokugawa clan defeated the Toyotomi clan and conquered all of Japan, the Law of One Castle per Province was promulgated in 1615, the year the Edo government started, and maintaining Tsugawa Castle, a branch castle, became difficult. The castle was abandoned in 1627 when the feudal lord was Yoshiaki Kato.