CastleFlatland castle (hirajiro)Next 100 Fine Castles No. 127
What makes this castle distinctive
Inside this star-shaped moat, children went to elementary school from the Meiji era until 2023.
Why?
Tatsuoka is a star-shaped fortified residence (jin'ya) built in the last years of the shogunate using a Western fortification method. After its buildings were torn down in the Meiji era, a school moved into the surviving kitchen hall, and the castle site became the grounds of Taguchi Elementary School. The school closed in March 2023, and the city now plans to remove the school buildings and bring the site closer to how it looked when it was built.[1][2][6]
Stone walls and moat that bend around the star's points
Where
The outer edge of the site. A path runs along the moat, so you can walk all the way around.
What to look at
The pointed corners that jut outward (bastions), where the stone walls and the moat turn sharply.
Why it's interesting
Pushing several sharp corners outward is a castle shape developed in Europe for the age of cannons. Guns placed at the tips of neighboring bastions could fire across each other's front and keep attackers away. Saku City says Japan has only two star forts of this kind: Goryokaku in Hakodate and Tatsuoka.[1][2][10]
Can you see it?
Visible from outsideFree to see from outside at any time.
The Odaidokoro, the only castle building left on site
Where
Inside the moat, on the grounds of the former Taguchi Elementary School.
What to look at
The exterior of the large building with white plaster walls and dark wooden boards.
Why it's interesting
When the castle was dismantled in the Meiji era, this kitchen hall was the only building left standing inside. A school moved here from a nearby temple and first used this very building, which began the long link between the castle site and the school.[1][2]
Can you see it?
Partly visibleExterior only. Interior visits require a reservation (usually groups of 20 or more, at least two weeks ahead, through Saku City's Cultural Properties Office). It opens to the public every year during the early-May holidays.
03
The star shape from the Goryokaku Observation Deck
Where
An observation deck on the hill north of the site, where the medieval Taguchi Castle stood. About 15–20 minutes up a trail from the trailhead.
What to look at
The outline of the star-shaped moat among the fields and houses.
Why it's interesting
On the ground the star shape is hard to grasp. The Saku City Tourism Association describes this deck as the only place where you can look down on it from above.[10]
Can you see it?
Visible from outsideFree, but you need to hike up a hill trail.
At a glance for visitors
Nearest station
20 min walk from JR Usuda Station
Climb
No climb
Time neededEditors' estimate
About 1 hour for a loop of the moat and the Guidance Center; allow roughly another hour to hike up to the observation deck.
You can walk freely around the outside of the site along the moat, at no charge. The former Taguchi Elementary School buildings still stand inside the moat, and official information does not say how much of the interior is open, so follow the signs on site. The Odaidokoro interior is by reservation (usually groups of 20+, at least two weeks ahead, via the Cultural Properties Office, 0267-63-5321) and opens to all during the early-May holidays. The Continued Japan 100 Castles stamp is outside the entrance of the Guidance Center (Goryokaku Deai no Yakata) and can be used even when the center is closed. Castle seals (goshuin-style) and the shop are available 9:00–16:00.
The Ogyu Matsudaira family had its seat at Okudono in Mikawa Province (today's Okazaki, Aichi), but most of its land was in Saku: 12,000 koku there against 4,000 koku at Okudono. It already ran 25 villages in Saku from a local office (jin'ya). As Japan grew unsettled in the 1860s, the 11th head, Matsudaira Norikata, decided to move the family seat to Shinshu, and in 1863 chose Tanoguchi as the site for a new jin'ya.[2]
02
Historical record
Designed by a lord who studied Western warfare
Matsudaira Norikata held senior shogunate posts, including army commissioner, army chief and acting senior councilor. He was well read in Western learning and was among the first to train his domain's troops in the French style. For his new jin'ya he used the bastion system credited to the French military engineer Vauban. Work began in 1864 and finished in 1867. The land, stone and timber were supplied from within the domain, and the cost came to over 40,000 ryo.[1][2]
03
Historical record
A jin'ya, not a castle, and never finished
A jin'ya was the office and residence of a small domain that did not have the rank to hold a full castle. Tatsuoka, too, was built around a palace that served as both the lord's office and his home. The star shape was meant for crossfire, but a gun battery was placed only on the western bastion, and the moat was dug around just three of the five points; about 270 m on the southwest and west sides was never finished. It is said that all the roof tiles were prepared but only about a tenth were ever used.[1][2][11]
04
Historical record
Torn down and scattered
Only a few years after it was finished, the domain was abolished, and in 1872 the castle was dismantled. Only the moat, the stone walls and the kitchen hall remained inside. The great hall, the study hall (shoin), the east service gate and a roofed gate were moved to various places in Saku, where they still stand. Norikata later took the name Ogyu Yuzuru and worked to found the Hakuaisha, forerunner of the Japanese Red Cross Society. A bust of him stands on the site.[1][2]
05
Historical record
A school inside the fort
In 1875 the Shoyu School moved from the nearby temple of Banshoin into the surviving kitchen hall, and the castle site became a school. It remained the grounds of Taguchi Elementary School for generations, so children studied inside the star-shaped moat. The site was designated a National Historic Site in 1934. Taguchi Elementary closed in March 2023 when four local schools merged.[1][2][6]
06
Historical record
From schoolyard to historic park
Anticipating the school's closure, Saku City drew up a basic plan for the site. It calls for removing the former school buildings, excavating to confirm what lies underground, and turning the site into a historic park, while studying whether original buildings can be marked out or rebuilt. So far the city has surveyed the stone walls, dredged the moat and expanded the visitor center. In April 2026 the center north of the site, Goryokaku Deai no Yakata, was renamed the Tatsuoka Castle Site Guidance Center.[3][5][6][7]
A jin'ya built around the lord's palace; it never had a keep.
The site today
The star-shaped moat, stone walls and earthen banks survive. Inside them stand the buildings and schoolyard of Taguchi Elementary School, which closed in 2023. A visitor center lies just north of the site, next to Goryokaku Park, and fields and houses surround it all.
Main buildings
Original
Odaidokoro (kitchen hall)
Part of the palace and the only original building left on site. It was also used as a school building. Interior by reservation; open to all during the early-May holidays.[1][2]
Original, relocated
Great hall, study hall, east service gate, roofed gate and others
Moved to other places in Saku after the castle was dismantled, where they still stand.[2]
Lost
Palace (goten)
The lord's combined office and residence, dismantled in 1872.[1][2]
Key facts
Type
Castle
Setting
Flatland castle (hirajiro)built on flat ground, defended by moatsEditorial article
Period
Early modern (1570s–1871)Editorial article
Keep (tenshu)
No keep was builtthe castle never had a keepEditorial article
Built by
Matsudaira Norikata (Ogyu Yuzuru)Japan Castle Foundation
Built
1864Japan Castle Foundation
Main lords
Matsudaira clan, Ogyū-Matsudaira clanJapan Castle Foundation
Abandoned
1871Wikipedia (ja)
Remains to see
Turrets or turret bases, Stone walls, Earthen ramparts, MoatsEditorial article
Designation
National Historic Site (Tatsuoka Castle ruins) (1934)Editorial article
Selection
Next 100 Fine Castles No. 127Japan Castle Foundation
Visiting
Access
Partly open
You can walk freely around the outside of the site along the moat, at no charge. The former Taguchi Elementary School buildings still stand inside the moat, and official information does not say how much of the interior is open, so follow the signs on site. The Odaidokoro interior is by reservation (usually groups of 20+, at least two weeks ahead, via the Cultural Properties Office, 0267-63-5321) and opens to all during the early-May holidays. The Continued Japan 100 Castles stamp is outside the entrance of the Guidance Center (Goryokaku Deai no Yakata) and can be used even when the center is closed. Castle seals (goshuin-style) and the shop are available 9:00–16:00.
About 30 minutes from the Saku IC on the Joshin-etsu Expressway. Free parking at the Guidance Center (about 10 cars) and Goryokaku Park (24 cars).[10]
Checked: 2026-10-03
Grounds opening hours
Not confirmedChecked: 2026-10-03
Time neededEditors' estimate
About 1 hour for a loop of the moat and the Guidance Center; allow roughly another hour to hike up to the observation deck.
Steps, slopes and footing
The site and the walk from the stations are flat. The observation deck on the Taguchi Castle hill is a 15–20 minute climb from the trailhead.[10]
Wheelchairs and strollers
Not confirmedChecked: 2026-10-03
Toilets and rest
Not confirmed
English signs / audio guide
No English information could be confirmed.
Seasons
In spring the cherry trees on the moat banks bloom, and the local preservation society serves tea to visitors at the visitor center.[6]
Photography
Not confirmed
Works, closures and restrictions
The city plans to demolish the former Taguchi Elementary School and excavate the site (timing not confirmed). Accessible areas may change during the work, so check with the Cultural Properties Office or the Guidance Center (0267-82-0230) before you go.[7][5]Checked: 2026-10-03
City museum inside Goryokaku Park, right next to the site, showing the work of Kawamura Gozo, a sculptor from Usuda who made his name in the United States.[13][10]
A Western-style school building from 1875, an Important Cultural Property and National Historic Site. Like Tatsuoka, it tells the story of early Meiji schools. About 11 minutes by car from the castle.[14][10]
Checked: 2026-10-03
Editors' guide
An editorial guide based on sources and confirmed information — not a first-hand visit report.
Who will enjoy it
Good for anyone who has seen Goryokaku in Hakodate, fans of the late-shogunate era, and those curious about a castle that looks nothing like a typical Japanese one. It is quiet and uncrowded, in a peaceful valley.
What makes it interesting
Walk the moat path and watch the walls and water turn sharply at each point. Then check the star shape from the observation deck, and the path you walked falls into place. Look too at the kitchen hall and the old school building inside the moat to grasp that this site was a school for nearly 150 years.
Before you go
There is no keep or large turret. The closed school buildings still stand inside the moat, and demolition and excavation are planned, so follow on-site signs about where you can go. It is a 20–25 minute walk from the station, and no bus service could be confirmed, so consider a taxi or car.
Ways to enjoy it
Start at the Guidance Center with its film and displays to learn who Matsudaira Norikata (Ogyu Yuzuru) was, then walk the site. If you have the energy, climb to the observation deck for the view from above. In spring the moat banks are lined with cherry blossoms.
Photos
Visitor reviews
Be the first to review
Have you visited this castle? We'd love to hear from you.
Write a review
Open questions
Sources differ on the start and finish dates. Saku City gives 1864–1867, while the designation text on Cultural Heritage Online gives a start in 1863 and completion in December 1866.
Because it had only one battery and a fairly narrow moat, some historians see it more as a lord's residence than a fortress built for real battle (an interpretation).
Saku City's pages word the Guidance Center's Monday-holiday rule differently. This article follows the facility page updated in September 2026.
The statement that Japan has only two star forts of this kind comes from Saku City.
Access within the site, the timing of the school demolition, toilets, accessibility and bus service from the stations could not be confirmed from official sources.
SuikoteiCC BY 4.0Wikimedia Commons
