Motosu Castle was built to protect the vital trade route between the Takeda's home territory in Kai Province and the Pacific Ocean via the Suruga Province. It was also the farthest reach of the Takeda's stable territory as the territory between here and the ocean was under their control at one point but under control of the Hojo or Imagawa at others. After the fall of the Takeda in 1582, the castle came under the control of the Tokugawa. After the pacification of this area, the trade route was still a vital commercial road into the interior of Japan so the fortifications at the base of the mountain were retained and used into the Edo Period making it difficult to accurately date which parts are of the original Takeda constructions or are Edo Period works.
The Lake Motosu tourist information center (April to October) has a model of the castle but I did not visit since it was November.
This was a really interesting and fun castle ruin and probably one of a kind. The castle itself is a fairly typical borderland ridge line mountain castle, but the ruins of the structures around the base of the mountain are really impressive. First, this castle sits on the edge of the Aokigahara forest. This is a deep forest around the base of Mt. Fuji for several kilometers covered in thick trees and lava rock. The woods is very difficult to walk through except on cleared paths because of the fallen trees, roots and loose small lava rock everywhere.
This lava rock was used in the construction of several structures and stone walls around the base of the mountain and castle some of which we don't even know their use of today. There are sections of long stone walls, some ring formations and a couple gates. Across the road from the base of the mountain (at the bus stop) a stone wall goes at least 2km deep into the forest. I did not walk the entire wall, only about 1km but I would not mind going back again to explore even more.
It seems that the highly porous lava rock also makes for a good substrate for growing moss. Most of the stones have a thick covering of moss adding to the mysterious and somewhat spooky atmosphere. For such a unique and interesting site I'm really surprised it's not more well known.
|English Name||Motosu Castle|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Features||trenches, stone walls|
|Access||Kawaguchiko Sta, Lake Motosu Sightseeing bus 46 mins to Sekirui Iriguchi bust stop (石塁入口).|
|Visitor Information||Mountain trails, open any time|
|Time Required||240 mins|
|Location||Kawaguchiko, Yamanashi Prefecture|
|Coordinates||35° 28' 22", 138° 36' 29"|
|Visits||November 23, 2018|
|Added to Jcastle||2019|