In 1582, as Takeda Katsuyori was feeling the pressure from Tokugawa and Oda forces invading his lands, Sanada Masayuki invited him to move to one of his strongest fortresses, Iwabitsu Castle. Sanada laid the foundation for a fortified home at the Karamete Entrance to Iwabitsu Castle. If you visit the site, you'll see that it's tucked away in a somewhat hidden valley and would have been a defensible and well fortified place for Katsuyori. Unfortunately, Katsuyori fell into a trap by one of his vassals, Oyamada Nobushige who was in league with the Oda. Oyamada convinced Katsuyori to come to Iwadono Castle in the Takeda homeland of Kai rather than fleeing Kai completely and moving into the Sanada lands in Kozuke. When Katsuyori arrived, the castle was barred and he was not allowed in. He fled Iwadono and eventually committed suicide at Mt. Tenmoku while being pursued by Takigawa Kazumasa, an Oda vassal. Even though Oyamada had joined with the Oda, Oda had him executed for his dirty betrayal of Katsuyori.
Seiryuin is best visited in a trip to Iwabitsu Castle. Start from Gobara Station and walk to Seiryuin and then walk the "Sanada Road" to Iwabitsu Castle. Gunma Haramachi is often given as the closest train station to Iwabitsu Castle but it is a long boring uphill walk. This route is much better and mostly wooded. After Iwabitsu Castle you can walk downhill all the way to Gunma Haramachi for the return trip.
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Features||trenches, stone walls|
|Access||Gobara Sta. (Agatsuma Line), 25 min walk|
|Visitor Information||mountain trials, be open any time.|
|Time Required||20 mins|
|Location||Higashiazuma, Gunma Prefecture|
|Coordinates||36° 33' 14.72" N, 138° 47' 49.52" E|
|Added to Jcastle||2016|
|Admin Year Visited||2016|
|Admin Visits||April 29, 2016|