It was likely built by the Kanai clan around 1504. The Kanai were allied with the Murakami for around 60 years until 1550 when, along with the neighboring Terao clan, they allied with Takeda Shingen when he attacked the Murakami's Arato Castle. The Murakami attacked both clans and despite aid from Takeda's ally Sanada Yukitaka, Terao Castle fell and the Terao fled to Uesugi Kagekatsu in Echigo. The fate of Kanaiyama Castle is not certain but it likely fell to the Murakami as well. After Takeda Shingen took Amakazari Castle, it served as his main fortification until Matsushiro Castle was complete. Kanaiyama Castle and Terao Castle likely became part of the larger Amakazari Castle network defending around Matsushiro Castle.
You can rent electric bicycles (or regular bicycles) at Matsushiro and easily visit Kanaiyama Castle or Kawanakajima from there. Along the mountain ridge are several small baileys and kofun. Beyond the huge horikiri is the last bailey with some stonework. I didn't actually make it there. Due to the cliff face beyond the large horikiri being covered in new fallen leaves and damp from the rain and frost, I decided it was too dangerous to go on. I made it to the other side and tried climbing up but it only looked like more slippery rock faces as far as I could see. I may try it again someday in better conditions.
|English Name||Kanaiyama Castle|
|Year Founded||1504 (?)|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Features||trenches, stone walls|
|Access||Nagano Sta.; Bus to Kawanakajima Battlefield, 40 min walk.|
|Visitor Information||park open any time, see notes for more details|
|Time Required||90 mins|
|Location||Nagano, Nagano Prefecture|
|Coordinates||36° 35' 2", 138° 12' 22"|
|Visits||December 2, 2016|