Natsukawa Castle




Natsukawa Castle Ruin is a flatland castle which was built in a marshy region. According to the Okayama Board of Education, the main bailey is rectangular measuring 77m from east to west and 57m from north to south. The western side of the bailey is protected by ishigaki (stone walls) 4 metres high assembled in Nozurazumi Style, and the eastern side is protected mainly by earthen ramparts. The stone wall foundation at the northwestern corner indicates that there could have been a yagura (turret) built there. This castle was built in 1559 by Mimura Iechika to protect the area from attacks by Ukita Naoie (whose son built the black castle keep at Okayama Castle). During the Siege of Bitchu-Takamatsu Castle, Natsukawa Castle became one of seven frontier castles that the Mori Clan used to protect their lands. There was a fierce battle between the troops under Inoue Arikage, the lord of Natsukawa Castle at that time, and forces loyal to Toyotomi Hideyoshi. After the battle, it came under the control of the Ukita Clan, and the castle was demolished. At the castle ruin, there is an extant gate (the former Natsukawa Chigyosho’s Somon 撫川知行総門) built during the Edo Period and moved to its current location. Natsukawa Castle is a good example of a fairly well preserved Sengoku Period marshland castle ruin in Okayama Prefecture.

Photos and profile by RaymondW.

Visit Notes

This small castle ruin is easily accessible by public transport and is only around 10 minutes walk from JR Niwase Station. It is a good example of a marshland castle, incorporating the surrounding streams and marshes as part of its water moat defences. It only takes around 30 minutes to do this little castle site. Along with nearby Niwase Castle Ruin, the two castle ruins can easily be done in around an hour.

  • Southwest Corner
  • Stone Walls West Side
  • Stone wall yagura foundation and NW Corner
  • Earthen embankment East Side
  • Moat East Side
  • Honmaru stone walls and Moat South Side
  • Moat South Side
  • Earthen embankment
  • Natsukawa Chigyosho’s Somon gate
  • Natsukawa Chigyosho’s Somon gate
  • Well
  • Main Bailey

Castle Profile
English Name Natsukawa Castle
Japanese Name 撫川城
Founder Mimura Iechika
Year Founded 1559
Castle Type Flatland
Castle Condition No main keep but other buildings
Designations Prefectural Historic Site
Historical Period Pre Edo Period
Features gates, water moats, stone walls
Visitor Information
Access Niwase Sta. (San'yo Line, Hakubi Line); 10 min walk
Visitor Information the castle is located on the grounds of a shrine; open year round.
Time Required 30 minutes
Website area.php?id=69
Location Okayama City, Okayama Prefecture
Coordinates 34° 38' 34.87" N, 133° 50' 49.85" E
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Added to Jcastle 2013
Contributor RaymondW
Admin Year Visited Viewer Contributed

(3 votes)
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19 months ago
Score 0++

Natsukawajō is a flatland castle originally built within marshland to make it more defensible. It is surrounded by a moat and consists of both ishigaki (stone ramparts) and dorui (earthen ramparts) around a central compound. There is an Edo period gate at the entrance to the site but this was relocated to the site from elsewhere (Natsukawa Chigyōsho Sōmon, or the main gate of the headquarters of the Natsukawa Fief, which was possibly established in 1679 along with the Togawa-Niwase Fief). Natsukawa Castle is located right next to Niwase Castle. When I visited the water in the moat had been drained for maintenance, which gave me a good view of the ishigaki and allowed me to envision the castle as it was originally built surrounded by marsh. Attacking Natsukawajō, I thought, would leave you stuck in the mud. In the northwest corner of the rectangular main bailey the ishigaki juts out and it is thought that this segment was a yaguradai (base for a turret).


Natsukawajō was founded in 1559 by Miura Iechika. In 1575 it was conquered by the powerful Mori Clan, who used it as a branch castle in their network of defences, installing their vassal Inoue Arikage as commander of the fort. In the Mori's war with Toyotomi Hideyoshi, Natsukawajō was a border castle. Toyotomi's forces attacked the castle in 1582 and Inoue defended it with a force of 800 men. Meanwhile, another Mori border castle, Bitchū-Takamatsujō was being besieged through flooding tactics. The Mori eventually lost and in 1586 Natsukawajō was controlled by their enemies the Ukita Clan who built the 4m high nozura-dzumi ishigaki (unworked stone-piled ramparts) which can still be seen today on the western side of the main bailey. In 1602, with the creation of Niwase Domain, Natsukawajō was abandoned and neighbouring Niwase-jin'ya was built up instead.


24 months ago
Score 1++
updated to 'no main keep but other buildings' for relocated gate.


75 months ago
Score 1++
I think they were cleaning up the moat when I came because the mizubori had been turned into a dorobori : 3