Shinagura Castle: Ruins of the Would-Be Rulers of Matsumoto

Wed, Jul 7, 2021

A while back we took a look at Igawa-jo, the precursor to Matsumoto Castle. (Igawa-jo was actually the precursor to the precursor to Matsumoto Castle but anyway…) Built in the 1330s, during the turbulent years when the Ashikaga clan wrested control of Japan from the Minamoto clan, ushering in the Muromachi Era, Igawa-jo served as the first stronghold for the Ogasawara clan, rulers of this Shinano region.

At the same time, another castle was being built in the hills to the north. This castle, Shinagura-jo, was the home of an unpredictable clan: the crafty Akazawas.


As an offshoot of the Ogasawara bloodline, the Akazawa clan ruled over the Asama region for two hundred and fifty years. When Takeda Shingen invaded Shinano from the south in 1550, Akazawa Saemon, giving no thought to how it might affect the annual family clambake, decided to ally with Takeda’s forces against his own Ogasawara relatives. With their treacherous jump to the side of the enemy, the Akazawa Clan was able not only to hold onto Shinagura Castle but take control of nearby Ibuka-jo away from the Gocho clan, vassals to the Ogasawaras.

But when the armies of the Tokugawa clan defeated Takeda’s forces and put the Ogasawaras back in charge of Shinano the cunning Akazawas once again switched sides, promising to help put on the best family clambake ever and remaining as the lords of Shinagura. But it wasn’t long before they began plotting once again to overthrow the Ogasawara clan and take total control of Shinano. The Ogasawaras found out about the scheme, however, and decided they’d had enough, clams or no clams, and in 1583 finished off the Akazawa clan for good.


Like most of Matsumoto’s (and Japan’s) castle ruins, the remnants of Shinagura-jo consist of little besides rocks and big ruts in the dirt. In its heyday, Shinagura Castle extended five hundred meters along a ridge overlooking the Metoba River valley. The ‘shukaku’ – the castle’s main enclosure – sat about a thousand meters above sea level.

Not to scoff at the effort, but having gone through all that trouble one might wonder why they didn’t go another fifty meters up to the actual top of the mountain and put the shukaku there. Maybe they were in a hurry to finish the castle before the O-Bon travel rush. Whatever the reason, they decided to just dig a big ditch behind the shukaku as if, after hacking their way up the steep slopes of the wooded mountains to a point a half mile above the valley floor, that would be the thing to take the wind out of the enemy’s sails.


Above, L to R: Site of the shukaku; the real top of the mountain; the ditch behind the shukaku.

The Akazawa lords themselves didn’t seem motivated enough to even bother with the shukaku. Just a short way up the mountainside they picked a spot and set up shop, building their residence, the Yashiki-daira, aloong with a shrine, the family temple and, because they couldn’t be bothered to walk down to the river, a well. This stone marker is about all that’s left.

In 1583, defeated by the Ogasawaras once and for all, the last ruling Akazawa, Kiyotsune, committed suicide. Upon this the castle was destroyed. According to one of the signs dotting the area, the stone walls that remain are much as they were almost five hundred years ago.

There are two ways to approach the remains of Shinagura Castle (not counting hacking your way up the backside of the mountain and traversing that moat behind the shukaku). The shorter path begins at a grassy lot along the road leading up over Shinagura Pass. Head up the path to the left behind the sign, looking out for where it splits, just a few meters along. Turning right gets you a steep but clearly-visible trail with ropes guiding you much of the way. Going straight pretty much gets you lost, recreating, perhaps, what it might have been like for any enemies trying to breach the castle.

The more interesting route begins at a bit to the east along the main road running with the river. Look for the sign pointing to the castle (稲倉城), 2 kilometers away. Though longer, this path up the mountain is wider and clearer and not nearly as steep (once you get to the gate at the end of the street), and you’ll get to check out tons of ‘kuruwa’, the old stone castle walls. Plus it’s a really cool walk.

Eventually you’ll come to a place where the entire mountain in front of you is plastered with mossy stone ramparts. You’ll also see a sign pointing you left, seemingly away from all the action. But follow it around, this is the way to the ridge and the place with all the ditches where those unpredictable, untrustworthy Akazawas centered their power over this place many centuries ago.

To put it bluntly, Shinagura is a bit out of the way. By car it’s accessible. By bicycle it’s reachable. By bus it’s pretty much untenable. And to be brutally honest, only if you are a Japanese castle ruin enthusiast with loads of time on your hands would I recommend giving this place priority over the many other places Matsumoto has to offer the visitor.

That said, the rock walls are really cool.

Yes this is a map to a public toilet, strategically placed at the corner of the road that leads up to a gate, into the woods, past all those cool rock walls and up to the Shinagura Castle ruins.