Ōtaki-jo — the 100,000-koku stronghold of Honda Tadakatsu, one of the Tokugawa Four Heavenly Kings (Kazusa Province, Chiba)

2026-04-172026-04-18

First, check the Ōtemon Gate!!

Hello! Shin here!

Saturday, May 27, 2023.

This time, I visited Ōtaki-jo in Ōtaki Town, Isumi District, Chiba Prefecture 🚙

It is well known as the castle of Honda Tadakatsu, one of the Tokugawa Four Heavenly Kings.

I actually came here once before with my kids,

but back then, I was so captivated by the beauty of the reconstructed main keep

that I didn’t even notice the defensive structures like moats and earthen walls… 😓

This time, I’ll make sure to take a proper look at those as well !!

As for Ōtaki-jo,

the impressive Ōtemon Gate（大手門） is located a bit away from the main castle ruins,

so if you’re visiting by car, I recommend changing parking lots accordingly.

First, here is the parking lot for viewing the Ōtemon Gate.

(Images will follow.)

As the image syas,

with this parking lot, parking is free for the first 60 minutes,

which means a fee will be charged after that…

However, this lot is relatively close to the Ōtemon Gate（大手門） (about a 1-minute walk),

so you won’t have to walk unnecessarily.

Also, when you head to the castle ruins later, you can simply use another free parking lot.

Of course, if you prefer to explore everything on foot, that’s a different story.

In that case, you can head straight to the free “Castle Town Parking Lot” from the beginning.

And here is Ōtaki Station (Isumi Railway), located right in front of the Ōtemon Gate（大手門）.

The Isumi Railway is a local line that enjoys a certain level of popularity among railway enthusiasts,

and some people even come here just to photograph the trains.🚃

(There was one person doing exactly that on this day as well.)

If you’re into trains, it might be a good idea to visit via the Isumi Railway 😀

And across from Ōtaki Station,

you’ll find the Ōtaki Town Tourist Information Center 😆

Inside, you can find a wide variety of souvenirs and samurai-themed goods.

Of course, there are items related to Honda Tadakatsu as well!!

Here is the Ōtemon Gate（大手門）!!

Its sheer size and presence will probably make you want to photograph this first, even before the station or the tourist information center 😅

Moving a bit closer for a shot.

This Ōtemon Gate（大手門） appears to have been relocated from its original site from the Sengoku period.

Even so, it’s something to be grateful for that it has been carefully maintained and restored over time.

Personally, I find it particularly interesting that the outer walls are said to be made of sedimentary rock—constantly retaining moisture, making them extremely difficult to penetrate by any means…

This is a shot of the Ōtemon Gate（大手門） from the opposite side.

The catchy phrase “Koedo of Bōsō”（房総の小江戸） gives a real sense of its cultural value.

I couldn’t find the original Ōtemon Gate site from the Sengoku period…

I was captivated by the impressive Ōtemon Gate,

but I couldn’t help wondering what the actual original gate site looked like.

Checking Google Maps,

it seems to be around this area…

Head right here,

and it seems to be somewhere near Ōtaki High School…

Following Google Maps,

I found a shrine near the “Ōtemon Gate site.”

This appears to be Hachiman Shrine.

No matter which castle site you visit, shrines were often regarded as guardian deities of the castle.

In the end, however, I wasn’t able to find the actual Ōtemon Gate site…

It’s a shame I couldn’t find the Ōtemon Gate site,

but I definitely want to see the Yakuimon Gate（薬医門）!!

There it is—the Yakuimon Gate（薬医門）!!

However, since it’s located within the grounds of Ōtaki High School,

it wouldn’t be appropriate to go inside for a close-up shot.

School premises are generally off-limits to unauthorized visitors, after all…

Now, heading back the way I came, I’ll finally make my way to the Ōtaki-jo ruins.

You can see the main keep in the distance.

Ōtaki High School is in the foreground.

Inspecting the dry moat and the bell tower of the Ninomaru!!

After checking the Ōtemon Gate and the nearby remains,

I’ll move the car to another parking lot to head to the Ōtaki-jo ruins.

This is the free “Castle Town Parking Lot,” the closest to the Ōtaki-jo ruins.

The area is fairly spacious, with room for about 30 cars.

There is also a small teahouse on the grounds where you can grab a meal.

There was a stone monument marking the “Ōtaki-jo ruins.”

It really gets a Sengoku fan’s heart racing…

I’ll head up this slope.

(Ōtaki-jo is a hirayama-style castle built on elevated ground.)

First, the must-see is the Karabori（空堀：dry moat)!!

When I visited before, I only gave it a quick look.

Thankfully, there’s an information board right in front of it.

Indeed, compared to a water-filled moat, it looks far more lethal if you were to fall in.

The Karabori（空堀：dry moat)—truly formidable!!

Now, please take a look at its condition in the video.

It has probably been partially filled in with soil over time,

but it’s likely that it was originally much deeper and more steeply constructed.

From there, I continue up the slope, heading further uphill.

A short way up the slope from the dry moat site,

there was also a place called Ninomaru Park.

Perhaps this was once the site of the Ninomaru（二の丸：second enclosure).

It seems there is a bell tower further back on the right.

I’ll go check it out.

Please take a look at it in the video as well.

It’s a fairly large bell tower.

A shot from a distance.

Including Ninomaru Park, perhaps this area once formed a single kuruwa (enclosure).

Leaving Ninomaru Park behind,

I finally make my way to the area where the main keep stands.

Learn about the history at the “Training Hall,” and be captivated by the imposing main keep

After climbing to the top of the slope,

the first thing that comes into view is this “Training Hall.”

The main keep is visible at the edge of my sight, which makes me eager to move on, but I’ll take my time and start here.

Inside, there are suits of armor worn by famous Sengoku warlords!!

On the right is Date Masamune, and on the left is Tokugawa Ieyasu.

Of course, they’re probably not authentic, but even so, it’s enough to get a Sengoku fan excited.

Further inside, there were more on display here as well!

From the right: Ii Naomasa, Sanada Yukimura, and Yamanaka Shikanosuke.

All of them are warriors who made their names known during the Sengoku period.

Once inside,

there was also a portrait of Honda Tadakatsu, the lord of Ōtaki-jo.

This is a list of castles that existed in what is now Chiba Prefecture during the Sengoku period.

There are an incredible number of them…

Some of them may no longer remain as castle sites,

but looking at this, it makes me want to visit them all someday. 😅

And then—

the main keep towering right in front of the “Training Hall”!!

It is, of course, a reconstructed keep, but even so, its imposing presence is captivating…

Unfortunately, the history museum was closed at that time.

It seems that Dorui（土塁：earthen walls) once surrounded this main enclosure.

I always make sure to check the defensive structures.

This is the Dorui（土塁：earthen walls).

Can you see how it’s slightly raised?

Now, I took a video of the main keep here, so please take a look.

With the “Training Hall” beside it,

I first take a shot from a distance… and then move closer.

It may not be an original keep, but together with the stone walls,

it still offers plenty to see.

This is the Yakuimon Gate（薬医門） located within the grounds of Ōtaki High School,

which I couldn’t get close enough to photograph.

It is the only surviving original structure of Ōtaki-jo.

There was also an information board about the fence.

It makes sense that wooden plank walls were vulnerable to fire and gunfire.

This is the fence extending around the main enclosure site.

With this, I conclude my exploration of Ōtaki-jo.

From the Ōtemon Gate and Yakuimon Gate to the dry moat and reconstructed main keep, there was plenty to see.

If you have the chance to visit southern Chiba, I highly recommend stopping by.

See you next time!!🏯

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