Niitakayama Castle Complete Guide | The Base of Kobayakawa Takakage and the Charm of the Continued Top 100 Japanese Castles
What is Niitakayama Castle?
Niitakayama Castle is a medieval mountain castle located in Hongō-chō, Mihara City, Hiroshima Prefecture. It was the base of Kobayakawa Takakage, the third son of Mōri Motonari. Built on a mountaintop at an altitude of 197.6 meters, this castle was selected as one of the Continued Top 100 Japanese Castles (No. 173) on April 6, 2017, and is also designated as a National Historic Site.
Located on the east side across the Numata River, it formed a sphere of influence for the Kobayakawa clan, in conjunction with Takayama Castle on the opposite bank. This vast mountain castle, spanning approximately 400 meters east-west and 500 meters north-south, functioned as a base for expansion into the Seto Inland Sea for about 45 years.
Currently, the site is meticulously maintained by local residents, and with ample signage, it has become a popular spot not only for castle enthusiasts but also for history buffs and hikers.
History of Shintakayama Castle
The Establishment of the Kobayakawa Clan and Takayama Castle
To understand the history of Shintakayama Castle, it is necessary to first know the lineage of the Kobayakawa clan. Doi Sanehira, the first head of the Kobayakawa clan, was ordered by Minamoto no Yoritomo to govern the Hongō area. Later, the fourth head, Kobayakawa Shigehira, built the main castle on Takayama, making it the Kobayakawa clan’s base.
During the time of the fifth head, Masahira, it is said that a secondary castle was built on Shintakayama, adjacent to the west across the Numata River. This secondary castle became the foundation of the later Shintakayama Castle.
Construction and Renovation by Kobayakawa Takakage
In 1552 (Tenbun 21), Kobayakawa Takakage, the third son of Mōri Motonari, extensively renovated this secondary castle, transforming it into Shintakayama Castle. Takakage was initially adopted into the Takehara Kobayakawa family, and later into the main Numata Kobayakawa family, moving from Kimura Castle to Takayama Castle. However, he soon built the more fortified and strategically superior Shin-Takayama Castle, making it his base.
Takakage’s reasons for choosing Shin-Takayama Castle were clear: its eastern side was a sheer cliff of exposed granite, making it a natural stronghold; its location allowed control of the Numata River’s water transport; and its strategic position was crucial for expansion into the Seto Inland Sea.
The Golden Age of the Kobayakawa Clan
With Shin-Takayama Castle as his base, Kobayakawa Takakage served as a senior retainer of the Mori clan, gaining control of the Seto Inland Sea. Takakage led a formidable navy, achieving great success in numerous battles, including the Battle of Itsukushima.
Shin-Takayama Castle was not merely a residence; it functioned as a military and political base along the Seto Inland Sea coast. From the mountaintop, one could see the surrounding territories, and it was a strategically important location controlling the Numata River’s water transport and land routes.
Relocation to Mihara Castle and Abandonment
In 1596 (Keicho 1), Kobayakawa Takakage built a new castle, Mihara Castle, and moved his base there. Mihara Castle was built as a coastal castle and became a larger political and military center. With this relocation, Niitakayama Castle was abandoned.
During the construction and renovation of Mihara Castle, materials such as stone walls were removed from Niitakayama Castle, so only a few remains of the original castle remain today. However, this very fact of “movement of materials” is important evidence that speaks to the historical connection between the two castles.
Structure of Niitakayama Castle
Layout and Overall Structure
Niitakayama Castle is a sturdy mountain castle with its main keep located on the mountaintop at an altitude of 197.6 meters, with a relative height difference of approximately 186 meters. Multiple enclosures (kuruwa) are arranged within an area of approximately 400 meters east-west and 500 meters north-south.
The structure, with enclosures extending from the mountaintop to the northern area and along the western ridge, fortified the entire mountain. The eastern side features a natural cliff of exposed granite, making it extremely difficult to attack, a strategically advantageous feature of the terrain.
Major Remains
Honmaru (Main Enclosure)
Located at the mountaintop, the Honmaru is the central enclosure of the castle. Even today, a flat terrain remains, hinting at the former building sites. From the Honmaru, one can see the surrounding mountains, the Numata River, and even the distant Seto Inland Sea, indicating its role as a surveillance and command post.
Nakanomaru (Middle Enclosure)
This enclosure is the second most important after the Honmaru, playing a role in protecting the Honmaru. It is believed that residential facilities and warehouses were located in Nakanomaru.
Nishinomaru and Kitanomaru
These enclosures were located on the ridges to the west and north, respectively, and served to prevent intrusion from each direction. Watchtowers were built in these enclosures, making them lookout and defensive strongholds.
Tsurui-no-dan
As the name “Tsurui” suggests, this enclosure had a well. Securing water was a matter of life and death for mountain castles, and Tsurui-no-dan was a crucial facility, essentially the castle’s lifeline. The remains of the well can still be seen today.
Kane-no-dan
This enclosure is believed to have housed a bell, which served to announce the time and issue emergency alarms.
Stone Walls and Defensive Facilities
Many stone walls were removed during the relocation to Mihara Castle, so only a limited amount remains today. However, the partially remaining stone walls demonstrate the high level of castle construction technology of the time.
Earthworks and moats were also strategically placed, creating a multi-layered defensive structure. In particular, trenches were constructed along the ridges, a measure taken to prevent enemy intrusion.
Relationship between Shin-Takayama Castle and Takayama Castle
Shin-Takayama Castle is closely related to Takayama Castle, located on the opposite bank of the Numata River. Takayama Castle was the ancestral residence of the Kobayakawa clan, and Shin-Takayama Castle was built as its secondary castle.
The two castles were in a position where they could see each other, and it is believed that they communicated through signal fire stations and other means. This strategy ensured control of the region by controlling both the east and west banks of the Numata River.
Currently, the ruins of Takayama Castle, Shin-Takayama Castle, and Mihara Castle are collectively designated as a national historic site under the name “Kobayakawa Clan Castle Ruins,” representing a valuable group of heritage sites that allow for a comprehensive understanding of the history of the Kobayakawa clan.
Shintakayama Castle as one of the Continued Top 100 Japanese Castles
On April 6, 2017 (Heisei 29), Shintakayama Castle was selected as the 173rd castle in the Continued Top 100 Japanese Castles. The Continued Top 100 Japanese Castles are selected as important castles second only to the Top 100 Japanese Castles, and this is proof of the high historical and cultural value of Shintakayama Castle.
The Continued Top 100 Japanese Castles stamp can be obtained at the Hongō Lifelong Learning Center and tourist facilities in Mihara City. For castle enthusiasts, it is an important item to commemorate their visit.
Highlights of Shintakayama Castle
Climbing Routes
There are several climbing routes to Shintakayama Castle. The most common is the route from the trailhead to the main keep, which takes about 30 to 40 minutes. The path is relatively well maintained, and there are plenty of signs, making it easy even for beginners to climb.
Along the hiking trail, you can see remnants such as baileys and moats, giving you a real sense of the structure of a Sengoku period mountain castle.
Views
The view from the main keep is one of the greatest highlights of Shintakayama Castle. On a clear day, you can even see the islands of the Seto Inland Sea. This view helps you understand why Kobayakawa Takakage chose this location as his base.
The 360-degree panorama, encompassing the surrounding mountains, the Numata River, and the townscape of Hongō, is well worth a visit.
Observation of Remains
By observing the remaining structures such as stone walls, well remains, baileys, and moats, you can learn about the reality of a Sengoku period mountain castle. The well remains at Tsurui-no-dan are particularly valuable, illustrating the importance of securing water for mountain castles.
Natural Environment
Shintakayama Castle ruins are surrounded by abundant nature, allowing you to enjoy the scenery of each season. From the fresh greenery of spring to the vibrant autumn leaves, each season offers a different face.
Access and Visit Information
Location
Hongo, Hongō-chō, Mihara City, Hiroshima Prefecture
Transportation Access
Access by Train:
- Approximately 15 minutes on foot from JR Sanyo Main Line “Hongo Station” to the trailhead
Access by Car:
- Approximately 5 minutes from Sanyo Expressway “Hongo IC”
- Parking available near the trailhead
Stamp Locations
The Continued Top 100 Japanese Castles stamp can be obtained at the following locations:
- Hongō Lifelong Learning Center
- Mihara City Tourism Association
Estimated Visiting Time
- Climbing Time: 30-40 minutes one way
- Visiting Time: 1-2 hours
- Total Time Required: Approximately 2-3 hours
Precautions When Visiting
- As it is a mountain castle, comfortable clothing and shoes are essential.
- Bring drinking water.
- Take insect repellent in summer.
- Watch your step in rainy weather or winter.
- Follow the signs.
Nearby Tourist Attractions
Takayama Castle Ruins
Located on the opposite bank of the Numata River, the Takayama Castle Ruins are another spot worth visiting along with Shin-Takayama Castle. It was the ancestral castle of the Kobayakawa clan, and you can see firsthand its relationship to Shin-Takayama Castle.
Mihara Castle Ruins
This is the site of Mihara Castle, to which Kobayakawa Takakage moved from Shin-Takayama Castle. Remains such as stone walls are still visible around JR Mihara Station, and it is directly accessible from the station. Visiting all three castles—Shin-Takayama Castle, Takayama Castle, and Mihara Castle—provides a comprehensive understanding of the Kobayakawa clan’s history.
Hongō Townscape
Hongō Town retains historical streetscapes and temples and shrines, making it a pleasant place to stroll.
Preservation and Maintenance of Shin-Takayama Castle
The Shin-Takayama Castle Ruins are preserved and maintained through the dedicated efforts of local residents. Volunteer efforts, including trail maintenance, signpost installation, and grass cutting, ensure a safe environment for visitors.
Given its designation as a national historic site, appropriate preservation and utilization are expected in the future. Efforts are underway to create an environment that is more accessible to a wider audience, without compromising its historical value.
Historical Significance of Niitakayama Castle
Niitakayama Castle was not merely a local mountain castle, but an important strategic point in the Seto Inland Sea region during the Sengoku period (Warring States period). It played a crucial role as the base of operations for the outstanding warrior Kobayakawa Takakage, and as a foothold for the Mori clan’s expansion into the Seto Inland Sea.
It also symbolizes the transition from mountain castles to coastal castles (Mihara Castle), representing a turning point from the Sengoku period to the early modern period. The history of Niitakayama Castle represents a turning point in the history of Japanese castles.
Summary
Niitakayama Castle is a sturdy mountain castle built by Kobayakawa Takakage, which functioned as a base for expansion into the Seto Inland Sea for approximately 45 years. It is a valuable cultural heritage site, selected as one of the Continued Top 100 Japanese Castles and designated as a national historic site.
Built on a mountaintop at an altitude of 197.6 meters, the castle consisted of numerous baileys, including the main keep, the central bailey, the western bailey, the northern bailey, the Tsurii-no-dan (fishing well terrace), and the Kane-no-dan (bell terrace). The castle’s layout, utilizing the natural fortifications of the sheer cliffs on the east side, showcases the pinnacle of castle-building technology from the Sengoku period (Warring States period).
Currently, the site is meticulously maintained by local residents, with well-developed hiking trails and signposts, making it a popular spot not only for history enthusiasts but also for general tourists and hikers. It’s easily accessible on foot from Hongō Station and can be visited in about 2-3 hours, making it a convenient stop.
Visiting Shin-Takayama Castle along with Takayama Castle Ruins and Mihara Castle Ruins will allow you to experience the history of the Kobayakawa clan and the transition period from the Sengoku period to the early modern era. When visiting Hiroshima Prefecture, be sure to visit Shin-Takayama Castle.
