Aoiyamajō was constructed in 1469 by Takeda Nobutaka of the Wakasa-Takeda Clan. Takeda Nobuaka is thought to have had his kyokan at the foot of the castle mount near to where Kōseiji and Obama Park are today. Aoiyamajō was the main base of the Wakasa-Takeda Clan until the construction of Nochiseyamajō in 1522 by Takeda Motomitsu. After that time it may have served as a satellite fortification of Nochiseyamajō to help guard the coast. The fort had excellent views of the bay.
Note: It is also said that Aoiyamajō was built in the Nanbokuchō Period, and it is attested as a Takeda base in 1432, though at that time the Wakasa-Takeda were not governors of Wakasa. The fort may have been rebuilt several times.
See also: Takeda Motonobu Yakata
And also: Nochiseyama Castle
Aoiyamajō is now the site of a nature park overlooking Obama. The castle mount has been extensively modified as part of the park, with roads and an observation deck. There are cleared spaces throughout. One cleared space along the ridge between the summit and Kōseiji looks like it could’ve been a bailey. Between this park where there is a statue of a soldier and the road which grants access to the observation area, I found what looked like a tatebori (climbing trench). Trenches are rumoured to be found here! So perhaps this is one. There is also a pass cut through the ridge, but since this is used as a path it is difficult to ascertain whether it was originally used as a trench at the castle or not. These features are the closest I came to confirming any fortification ruins. The site is accessed from trails either side of Kōseiji. The temple itself is very nice, and the entrance to the trail to the northeast has what looks – if we use our imaginations – like a moat and ramparts, though these are unrelated to any medieval fortifications, and were probably built as part of the park since there is a war memorial stele directly above. From the castle mount the ruins of Obama Castle are visible.
|English Name||Aoiyama Castle|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Access||Obama Station on the Obama Line; 20 minute walk to Obama Park|
|Visitor Information||24/7 free; park|
|Time Required||30 minutes|
|Location||Obama, Fukui Prefecture|
|Coordinates||35° 29' 37.00" N, 135° 43' 55.34" E|
|Added to Jcastle||2023|
|Admin Year Visited||Viewer Contributed|