Jōmineyamajō, also called Jōǵaminejō, is known as a fortification site from its name and scant remains, but the history is unknown. Due to its location, it is speculated that it was built by the Nishina Clan to protect their territory from invasion from the east. It may have been a satellite fortification of Raidenjō to the northeast, but this is not verified.
Jōmineyamajō is a yamajiro (mountaintop castle) ruin in Yasaka Township, Ômachi Municipality. Features include a segment of ridge perhaps used as a bulwark, and flattened areas used as baileys. The earthworks are not well developed and may represent a relatively old fortification. The exact extent of the fort, including what was likely the main bailey, is hard to determine because this castle ruin has been largely destroyed by landslides. The cliff created by the landslide is so enormously large, and the remaining earth at the edge of the cliff extends jutting over blank space, so that it is incredibly dangerous to approach. As I approached the edge of the cliff, the earth seemed loose under my feet, almost cushion-like, and I sensed there must be only a meter or so of earth between me and a deathly drop. In general this site is overgrown and dangerous to explore with little to justify the risk and effort.
|Nishina Clan (theorised)
|Pre Edo Period
|Shinano-Ômachi Station on the Ôito Line; rental e-bike
|24/7 free; mountain
|Ômachi, Nagano Prefecture
|36° 29' 12.41" N, 137° 55' 3.11" E
|Added to Jcastle
|Admin Year Visited
|Friends of JCastle