Tsubai Castle Ruins: Remains of a Sengoku Period Mountain Castle on the Yada Hills and the Struggle Between Shima Sakon and Matsunaga Hisahide
Tsubai Castle Ruins are the remains of a Sengoku period mountain castle located in Heguri-cho, Ikoma-gun, Nara Prefecture. Built on the ridge of the Yada Hills, this castle has a long, narrow shape, stretching approximately 300-310 meters from north to south. Many of its remains, including baileys, deep moats, and earthworks, are well-preserved. Historically, it is a historically important castle, having been the site of numerous battles between Shima Sakon, a retainer of Tsutsui Junkei, and Matsunaga Hisahide, who was based at Shigisan Castle, during the late Sengoku period.
Currently, local volunteers have been working to maintain the site, installing hiking trails and signs, making it easy to visit the castle ruins. The remains, integrated with the natural landscape of the Yada Hills, are a valuable historical and cultural resource that conveys the appearance of a military base in Yamato Province during the Sengoku period.
Location and Topographical Characteristics of Tsubai Castle Ruins
Tsubai Castle Ruins are located near the southern end of the Yada Hills, which run north-south along the western side of the Nara Basin. Between the Yada Hills and the Ikoma Mountains lies the Heguri Valley, centered on the Tatsuta River, and Tsubai Castle was built in an excellent position overlooking this valley.
The castle ruins are situated on a ridge at an altitude of approximately 250-280m, offering a strategically important location with panoramic views of the Heguri Valley to the east and the Shigi Mountains to the west. The relationship with Shigi Castle is particularly important; this view held significant military importance in the battles fought between the two castles during the late Sengoku period.
The location on the ridge of the Yada Hills also offers excellent defensive advantages. The ridge, surrounded by steep slopes, makes enemy incursions difficult and is easily defended by a small force. The castle’s layout, which makes maximum use of this terrain, is a major characteristic.
Details of the Layout and Remains of Tsubai Castle
Tsubai Castle has a long, narrow layout running north-south, reaching a total length of approximately 310m. The castle grounds are slightly lower in the center, dividing them into northern and southern baileys. The higher northern section is considered the main bailey and is thought to have played a central role in the castle’s defenses.
Structure of the Northern Baileys
The northern baileys are the central part of the castle and consist of multiple baileys, including the main bailey. Clear earthworks surround the main bailey, enhancing its defensive capabilities. Deep moats are provided between the baileys, demonstrating various measures taken to prevent enemy intrusion.
Notably, traces of stone walls can be found in a small area. Examples of stone walls in mountain castles in Yamato Province are limited, making this an important clue in considering the construction period and renovation history of Tsubai Castle.
Characteristics of the Southern Baileys
Although slightly smaller in scale than the northern baileys, the southern baileys are arranged in a stepped pattern. A large moat is located at the southern end, clearly defining the castle’s boundaries. This moat is remarkably deep and wide, demonstrating the high level of defensive awareness at Tsubai Castle.
Arrangement of Moats and Earthworks
Multiple moats are strategically placed within the castle grounds, demarcating the baileys. These moats are cut-throughs and are still clearly visible today as deep depressions. Earthworks surround the main baileys, varying in height depending on the location, but some sections reach a maximum height of 2-3 meters.
These remains are valuable examples illustrating the development of mountain castle construction techniques from the Muromachi period to the Sengoku period, and are important resources for understanding the level of military engineering at that time.
History of Tsubai Castle and Changes in Lords
While there are no definitive historical records regarding the construction period or early lords of Tsubai Castle, their changes can be inferred to some extent from tradition and local history.
Construction by the Tsubai Clan
There is a tradition that the castle was initially built by the Tsubai clan, a local powerful family. The Tsubai clan was a regional powerful family based around the Heguri Valley, and it is believed they established the castle in this location during the Muromachi period. Its location on the ridge of the Yada Hills was ideal for controlling and defending the Heguri Valley, making it a perfect base for a powerful local figure.
Relocation to the Shima Clan
Later, the castle is said to have been moved to the Shima clan. The Shima clan were powerful vassals of the Tsutsui clan, and Shima Sakon (Shima Kiyooki) in particular was a samurai known as one of the “Three Chief Retainers of Tsutsui.” While the exact circumstances of how Tsubai Castle became the Shima clan’s residence are unclear, it is highly probable that it was given to the Shima clan as a base for controlling the Heguri Valley as the Tsutsui clan’s power expanded.
Struggle with Matsunaga Hisahide
At the end of the Sengoku period, Tsutsui Junkei and Matsunaga Hisahide were fiercely opposed in Yamato Province. Matsunaga Hisahide, using Shigisan Castle as his base, aimed to control Yamato Province and attacked various castles under the control of the Tsutsui clan. Tsubai Castle was also a target, and it is said that numerous battles for its control took place.
Shigisan Castle and Tsubai Castle were only a few kilometers apart in a straight line, and the battles between them were fierce. It is believed that Shima Sakon, as a senior retainer of Tsutsui Junkei, defended Tsubai Castle and resisted attacks from Matsunaga’s forces.
Oda Nobunaga’s Conquest of Yamato and the Abolition of Castles
During the Tensho era, Oda Nobunaga advanced his conquest of Yamato Province. In 1580, Nobunaga ordered Tsutsui Junkei to relocate to Koriyama Castle and instructed the demolition of various castles within Yamato Province. It is believed that Tsubai Castle was abandoned and became a ruined castle due to this “One Castle Per Province” decree.
This policy led to the disappearance of many mountain castles in Yamato Province, but fortunately, the remains of Tsubai Castle have been well preserved and remain to this day.
Shima Sakon and Tsubai Castle
Shima Sakon (Shima Kiyooki) is the warrior most strongly associated with Tsubai Castle. Sakon served Tsutsui Junkei and, along with Matsukura Ukon and Mori Shima, was known as one of the “Three Chief Retainers of Tsutsui.”
While much of Sakon’s early life remains unknown, it is certain that he was a senior retainer of the Tsutsui clan and based in the Heguri Valley area. It is believed that he once resided at Tsubai Castle and contributed to the expansion of the Tsutsui clan’s power from this location.
Later, Sakon became a retainer of Ishida Mitsunari and became widely known for his exploits in the Battle of Sekigahara. His bravery and strategic brilliance were so highly regarded that a popular song remains: “There are two things that are too good for Mitsunari: Shima Sakon and Sawayama Castle.”
Tsubai Castle is attracting the interest of history enthusiasts as a castle where Shima Sakon, who would later become a famous general, may have spent his youth.
The Relationship Between Matsunaga Hisahide and Shigisan Castle
When discussing the history of Tsubai Castle, the existence of Matsunaga Hisahide and Shigisan Castle is indispensable. Matsunaga Hisahide is known as a ruthless warlord of the Sengoku period and fiercely fought with the Tsutsui clan for control of Yamato Province.
Hisahide advanced into Yamato Province around 1559, expanding his power from Shigisan Castle as his base. Shigisan Castle was a strong mountain castle built on a mountain approximately 400m above sea level, and was a strategic point controlling western Yamato Province.
Tsubai Castle is located east of Shigisan Castle, across the Heguri Valley, and the two castles were within sight of each other. Therefore, Tsubai Castle was an important base for the Tsutsui clan to monitor Shigisan Castle and keep the movements of the Matsunaga clan in check.
In 1577, Matsunaga Hisahide rebelled against Oda Nobunaga and holed up in Shigisan Castle. Ultimately, the castle fell, and Hisahide committed suicide. This downfall of the Matsunaga clan solidified the Tsutsui clan’s dominance in Yamato Province, and it is believed that the military importance of Tsubai Castle also changed.
Access and Visiting Tsubai Castle Ruins
Thanks to recent improvements by local volunteers, Tsubai Castle Ruins are now easily accessible. Hiking trails are maintained, and signs are in place, making it easy for first-time visitors to explore the castle ruins without getting lost.
Access Method
The nearest landmark is the “Yamatoji Heguri” roadside station, and Tsubai Castle Ruins are located to the east of it. There are multiple entrances to the castle, but the main routes are as follows:
Route from the South: There is a path that ascends from Jōnenji Temple via Miyaurayama Kofun (ancient burial mound), and this route leads to the moat at the southern end. The climb is relatively gentle, allowing you to begin your tour from the southern group of enclosures within the castle ruins.
Route from the North: There is also a path leading up from the grounds of Tsubai Kasuga Shrine, which is thought to be the main approach to the saddle between the northern and southern groups of enclosures.
Points to Note During Your Visit
A visit to the castle ruins takes approximately 1-2 hours. Keeping the following points in mind will make your visit more fulfilling:
- Southern Moat: A large moat marking the boundary of the castle area; pay attention to its depth and width.
- Southern Enclosures: You can see multiple enclosures arranged in a stepped pattern.
- Central Saddle: A low-lying area separating the northern and southern groups of enclosures, key to understanding the castle’s structure.
- Northern Main Enclosure: The central part of the castle; look for traces of earthworks and stone walls. 5. View: From near the main enclosure, you can enjoy views of the Heguri Valley and the Shigi Mountain area. The view at sunset is particularly renowned for its beauty.
Precautions for Visiting
- As it is a mountain castle, comfortable clothing and shoes are essential.
- In summer, vegetation can be overgrown, making visits difficult.
- Bring drinking water and take precautions against heatstroke.
- To protect the remains, please do not climb on the earthworks or stone walls.
- Avoid visiting alone; it is recommended to visit with others if possible.
Historical and Cultural Value of Tsubai Castle Ruins
Tsubai Castle Ruins is a historical and cultural resource with value beyond mere castle ruins. Its importance can be summarized as follows:
Value in the Study of Mountain Castles of the Sengoku Period
Tsubai Castle Ruins is a valuable example demonstrating the development of mountain castle construction techniques from the Muromachi period to the Sengoku period. The castle exhibits typical characteristics of mountain castles from this period, such as its long, narrow layout running north-south, multiple moats for division, and earthen ramparts for defense.
Furthermore, the regional characteristics of Yamato Province are also important. Castles using stone walls were limited in Yamato Province, and the traces of stone walls found at Tsubai Castle are valuable resources for understanding the adoption and development of castle-building techniques in the region.
Position in the Sengoku History of Yamato Province
Tsubai Castle was the site of an actual battle for control during a crucial period in the Sengoku history of Yamato Province: the conflict between the Tsutsui and Matsunaga clans. Its connection to the famous warrior Shima Sakon also enhances the historical value of the castle ruins.
It was also influenced by Oda Nobunaga’s pacification of Yamato and the “One Castle Per Province” decree, policies symbolizing the transition from the Sengoku period to the early modern period, making it an important site marking a turning point in history.
Cultural Resources that Convey Local History
For Heguri Town, the Tsubai Castle ruins are an important cultural resource symbolizing the history of the region. The castle ruins, integrated with the natural environment of the Yada Hills, serve as a cornerstone of the local residents’ identity, and preservation and maintenance activities are continuously carried out by local volunteers.
In recent years, it has also attracted attention as a tourist resource and is included in Heguri Town’s “Heguri Walking Map,” contributing to regional development.
Visiting Surrounding Historical Spots
When visiting the Tsubai Castle ruins, visiting surrounding historical spots in conjunction will allow you to gain a deeper understanding of the region’s history.
Shigisan Castle Ruins
Shigisan Castle ruins, which served as a base for Matsunaga Hisahide, are worth visiting together with Tsubai Castle, as it was a castle that faced it. Remains of the castle are scattered around the grounds of Shigisan Chogosonshi-ji Temple, allowing you to experience a mountain castle with a different scale and structure from Tsubai Castle.
Jōnen-ji Temple and Tsubai Kasuga Shrine
These temples and shrines, located at the entrance to Tsubai Castle, may have a history related to the castle. In particular, Tsubai Kasuga Shrine is thought to have a connection to the Tsubai clan and is important for understanding the history of the region.
Miyaurayama Kofun (ancient burial mound)
This burial mound is located along the path leading to the Tsubai Castle ruins and indicates that this area has been a place of human habitation since ancient times. Visiting it along with the castle ruins allows you to feel the layered history of the region.
Historical Landscape of Heguri Valley
The Heguri Valley, viewed from the main enclosure of Tsubai Castle, presents a rural landscape that has continued since ancient times. Imagining that the warlords of the Sengoku period saw the same scenery deepens our understanding of history.
Preservation of Tsubai Castle Ruins and Future Challenges
Thanks to the efforts of local volunteers, preservation of the remains and improvement of the viewing environment at Tsubai Castle ruins are progressing, but continued efforts are needed.
Current Preservation Status
The castle ruins are located within a forest, and there are no buildings or other structures, but the civil engineering remains such as baileys, earthworks, and moats are well preserved. Recent improvements have created hiking trails and installed signs, making it easier for visitors to see the ruins.
However, as is unique to mountain castles, there are concerns about the burial of ruins due to overgrown vegetation and deterioration due to natural factors such as erosion from wind and rain.
Future Challenges and Prospects
To pass on the value of Tsubai Castle Ruins to future generations, the following initiatives are important:
- Continuous Maintenance: Regular maintenance is necessary, including trail maintenance, grass cutting, and sign updates.
- Promotion of Academic Research: Excavation and surveying are expected to provide a more detailed understanding of the castle’s structure and history.
- Strengthening Information Dissemination: It is important to let more people know about the value of the castle ruins by improving brochures and websites.
- Educational Use: Incorporating castle ruin visits into local school education will help pass on history to the next generation.
- Utilization as a Tourism Resource: By utilizing the site as a tourism resource, while ensuring proper preservation, it can contribute to regional development.
A major challenge for the future is for local residents, government officials, and researchers to cooperate in achieving both the preservation and utilization of the Tsubai Castle ruins.
Summary: The Memories of the Sengoku Period Told by Tsubai Castle Ruins
Tsubai Castle Ruins are a valuable mountain castle remains from the Sengoku period, located on the ridge of the Yada Hills. The castle grounds, spanning approximately 300 meters from north to south, feature well-preserved baileys, earthworks, and moats, conveying the castle-building techniques and strategic thinking of the time.
From its construction by the Tsubai clan, through the struggle between Shima Sakon and Matsunaga Hisahide, to Oda Nobunaga’s pacification of Yamato and the subsequent abandonment of the castle, Tsubai Castle played a crucial role in the history of the Sengoku period in Yamato Province. The connection to Shima Sakon, a warlord who left his mark on history, gives the castle ruins a special appeal.
Thanks to recent maintenance efforts by local volunteers, access to the castle ruins has improved, making it a popular spot not only for history enthusiasts but also for hikers. The view from the main enclosure is magnificent, offering a panoramic vista of the Heguri Valley and Mount Shigi, leaving a lasting impression on visitors.
Tsubaki Castle Ruins are not merely historical relics, but a living cultural resource symbolizing the region’s history and culture. To pass on this valuable heritage to future generations, continuous preservation efforts and initiatives to widely communicate its value are essential.
Experience the spirit of the warriors who lived through the turbulent Sengoku period at Tsubai Castle Ruins. Why not experience the weight of history amidst the natural beauty of the Yada Hills?
