Onjōyama-toride, also known as Onjōyama-monomidai (look-out), is thought to have served as a branch fort of nearby Haibarajō. The fort, chiefly used as a look-out post, consisted of a small flattened area in two parts of around 10m by 14m surrounded by dorui (earthen ramparts). Unfortunately, the site saw excavation of earth for use as backfilling in construction projects and as a result all ruins of the fort were destroyed around 1993. Who knows where the earth which was once sculpted into ramparts ended up! Scattered to the winds.
See Haibara Castle for more information.
I tried very hard to find something definitive here but it was ultimately in vain because the site of this fort site, Onjōyama-toride, has been completely obliterated. The layout of the mount is nonetheless quite interesting as it terminates in a cultivated area with a good view of the fertile slopes of Nakayama. So at least I was able to get a sense of how the area would have been suitable for a small fortified look-out like Onjōyama-toride. And nearby I also found the site of an ancient state-owned ranch. I had no idea that such places existed. It seems these pastures, subordinated to the Imperial Ministry of War, were used as places to breed and keep horses for use by the Imperial army, as well as for farming. This site, the Haibara-maki, was one of two in Chikuma District (though another source I found includes an additional smaller one), and one of sixteen in Shinano, that province accounting for half of all such ranches in eastern Japan. A signboard I found by chance informed me of this.
|English Name||Onjouyama Fort|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Access||Nearest station is Hirata Station on the Shinonoi Line|
|Visitor Information||Reclaimed by Nature|
|Time Required||20 minutes|
|Location||Matsumoto, Nagano Prefecture|
|Coordinates||36° 10' 49.48" N, 138° 0' 24.05" E|
|Added to Jcastle||2021|
|Admin Year Visited||Viewer Contributed|