Haruyamajō is attested from 1369, when the castellan was Commander Kamitôno, who had been installed by Uesugi Tomofusa, governor of Shinano. The Murakami Clan and other local clans rebelled against the governor and besieged Haruyamajō for two months. (This earlier history of the fort is described on (Japanese) Wikipedia, but I can find no other references to it and the article does not have any citations; the ruins we see today date to the Sengoku period.)
Haruyamajō was used in the wars between Uesugi Kenshin and Takeda Shingen in control for northern Shinano. It is speculated that the Inōe Clan, who had their residences in the valley below, maintained the fort in the Sengoku period. The Inōe were split over whether to support the Uesugi or the Takeda. In 1556 the Inōe came under the sway of Takeda Shingen, and Haruyamajō was used by Takeda forces, who referred to it as the Watauchi-yōgai. It is not known who was the castellan(s) at this time, but various Takeda vassals have been suggested as candidates, such as the Tominaga or Watauchi. Soon after, however, Haruyamajō was besieged and destroyed by Imashimizu Tarōjirō, a vassal of the Uesugi-alligned Takanashi Clan.
It is also said that Uesugi Kagetora briefly maintained a camp here between the death of Uesugi Kenshin in 1578 and his own demise shortly thereafter.
Haruyamaôjō ('Spring Mountain Great Castle') is a yamajiro (mountaintop castle) ruin in Wakaho Township, Nagano Municipality. The ruins consist of earthworks in the form of kuruwa (baileys), horikiri (trenches) and dorui (earthen ramparts). The layout is a of a simple ridgeline castle with a series of baileys made by flattening the ridge, separated by trenches. Most of the baileys have some dorui banked up, particularly to the rear above the trenches (where it would've been easiest to pile the excavated earth). There is a large forward trench which is where the trail enters the ruins.
Haruyamaôjō has a satellite fort, Haruyamakojō ('Spring Mountain Little Castle'), which is located further up the mountain. Together both sites are referred to as Haruyamajō ('Spring Mountain Castle'). I hiked up to this site starting from the temple Rendaiji, which is to the east of the castle mount.
|English Name||Haruyamaoh Castle|
|Founder||Before 1369; Sengoku Period|
|Year Founded||Kamitôno Clan; Inōe Clan|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Artifacts||Kuruwa, Dorui, Horikiri, &c.|
|Access||Hike from Rendaiji Temple to the east of the castle mount|
|Visitor Information||24/7 free; mountain|
|Time Required||60 minutes|
|Location||Nagano, Nagano Prefecture|
|Coordinates||36° 36' 46.44" N, 138° 15' 55.44" E|
|Added to Jcastle||2023|
|Admin Year Visited||Viewer Contributed|
|Friends of JCastle|