Isawa Castle was built in 802 by Sakanōe Tamuramaro after his series of victories against the Emishi tribesmen the previous year. The Chinjufu-shōgun, under the command of the Seiitai-shōgun, was relocated from Tagajō to Isawajō following the expansion northward of the Yamato state. The Emishi were eventually subjugated or migrated to Ezo (Hokkaidō). Isawa no Ki remained the seat of the Chinjufu-shōgun until 1083 when Minamoto Yoshiie became governor of Mutsu Province.
Isawa Castle was a classical era Jōsaku style fort. These earlier types of fortification consisted of wooden palings, moats and pounded earth walls with archer platforms and imposing gates, resembling walled administrative centers or palaces in their layout. Isawa Castle is rendered Isawa no Ki in contemporary Japanese but is now also called Isawajō (same kanji). I also call it Isawa no Saku. Nothing remains today except some mounds of earth, and the site is mostly fields and rice paddies. There is also a shrine on the former castle grounds, Chinjufu-Hachimangū, which venerates the historical figures connected with the construction of the castle. I found some description boards and stone markers. There are some earthwork remains here but I did a bad job photographing them. The land is mostly fields now.
|English Name||Isawa Castle|
|Alternate Names||Isawa no Saku|
|Castle Condition||Ruins only|
|Designations||National Historic Site|
|Historical Period||Pre Edo Period|
|Access||Kanegasaki Station on the Tohoku Main Line; 45 minute walk|
|Visitor Information||Free, 24/7|
|Time Required||45 minutes|
|Location||Oushuu, Iwate Prefecture|
|Coordinates||39° 10' 46", 141° 8' 8"|
|Year Visited||Viewer Contributed|
|Added to Jcastle||2018|