Akutagawayama Castle: The Complete Picture of Miyoshi Nagayoshi’s Castle, a Former Top 100 Japanese Castles
About Akutagawayama Castle
Akutagawayama Castle is a Sengoku period mountain castle located in Takatsuki City, Osaka Prefecture. Built on Mount Miyoshi (commonly known as Shiroyama), at an altitude of 182.69 meters, it is known as a natural stronghold, surrounded on the north, west, and south sides by the Akutagawa River valley. From the summit, it boasts an excellent location offering panoramic views of the Osaka Plain, from the Ikoma Mountains to Osaka City.
In March 2017, it was selected as one of the “Top 100 Japanese Castles” by the Japan Castle Association, and in November 2022, it was designated a National Historic Site. As one of the most prominent mountain castles of the Sengoku period, it remains an important historical site visited by many castle enthusiasts and history lovers.
The castle grounds extend approximately 500 meters east-west and 400 meters north-south, centered around the main enclosure and eastern enclosure, with numerous defensive structures such as moats, earthen bridges, and vertical earthworks. While no buildings remain, the remains of the enclosures, stone walls, and earthworks are well-preserved, conveying the characteristics of a mountain castle from the late Sengoku period.
History of Akutagawayama Castle
Construction by Hosokawa Takakuni
The first mention of Akutagawayama Castle in historical records is in the “Utsuyama-ki,” dated January of Eisho 13 (1516). It records that a renga (linked verse) gathering, in which the renga poet Socho participated, was held at “Akutagawa Shinjo,” where Nose Yorinori served as lord.
Akutagawayama Castle is believed to have been built between Eisho 12 (1515) and Eisho 13 (1516) by Hosokawa Takakuni, the shogunal deputy governor of Settsu and Tanba provinces. According to the “Kawarabayashi Masayori Chronicle,” records indicate that 500 and 300 laborers were mobilized day and night, demonstrating the rapid pace at which the castle was constructed.
Hosokawa Takakuni, as the Kanrei (deputy shogun) of the Muromachi Shogunate, built Akutagawayama Castle to strengthen his political control over the Kyoto area. This castle played a crucial role as a base in Settsu Province.
Function as the “Shugosho” (Provincial Governor’s Office) of Settsu Province
Akutagawayama Castle was not merely a military base; it also functioned as the “Shugosho” of Settsu Province. A Shugosho was a government office established by a Shugo Daimyo (provincial governor) for the purpose of governing their territory, functioning as the center of administration, justice, and military affairs.
During Hosokawa Takakuni’s time, Akutagawayama Castle served as the center of Settsu Province’s rule, playing a role in controlling the samurai of the surrounding regions. Akutagawayama Castle was unique in that it combined a mountain castle with political functions.
The Era of Hosokawa Harumoto
After Hosokawa Takakuni, Akutagawayama Castle became the residence of Hosokawa Harumoto. During the Tenbun era (1532-1555), Harumoto used Akutagawayama Castle as his base to expand his power in the Kinai region.
In 1539 (Tenbun 8), Harumoto developed Akutagawa-juku (the castle town), strengthening its function as a political and economic center. During this period, Akutagawayama Castle developed into a complex castle system, integrating the mountain castle and the flatland castle (Akutagawa Castle) at the foot of the mountain.
The Residence of Miyoshi Nagayoshi, the Unifier of Japan
The most important period in the history of Akutagawayama Castle is the era when Miyoshi Nagayoshi became its lord. In 1553 (Tenbun 22), Nagayoshi expelled Hosokawa Harumoto and entered Akutagawayama Castle. As a result, Akutagawayama Castle became the headquarters of the Miyoshi regime.
Miyoshi Nagayoshi was a Sengoku period daimyo who, before Oda Nobunaga, was called a “ruler of Japan.” He controlled five provinces—Settsu, Kawachi, Izumi, Yamashiro, and Tanba—centered around the Kinai region, and held real power within the Muromachi Shogunate. The period when Nagayoshi was based at Akutagawayama Castle was precisely the peak of the Miyoshi regime.
At Akutagawayama Castle, Nagayoshi built not only a military facility but also a palace to demonstrate his power. This is a unique example for a mountain castle at the end of the Sengoku period, illustrating Nagayoshi’s political ambition and the extent of his power.
Around 1563, Nagayoshi moved his base to Iimoriyama Castle (Daito City and Shijonawate City, Osaka Prefecture), but Akutagawayama Castle continued to function as an important base for the Miyoshi clan.
Oda Nobunaga’s Invasion of Settsu and Akutagawayama Castle
In 1568, when Oda Nobunaga entered Kyoto with Ashikaga Yoshiaki, the power dynamics in the Kinai region changed dramatically. When Nobunaga invaded Settsu, Akutagawayama Castle came under his control.
Nobunaga appointed Wada Koremasa, one of the “Three Guardians of Settsu,” as the lord of Akutagawayama Castle. Koremasa served as Nobunaga’s vassal and governed Settsu Province, but was killed in the Battle of Shirai-gawara in 1571.
Afterward, Takayama Tomoteru (father of the Christian daimyo Takayama Ukon) became the castle lord, but Akutagawayama Castle was abandoned around 1573. During this period, Oda Nobunaga developed Takatsuki Castle as his new base, marking the end of Akutagawayama Castle’s role.
Layout and Remains of Akutagawayama Castle
Location Utilizing Natural Fortifications
Akutagawayama Castle is a mountain castle built skillfully utilizing the cliffs and valleys on the east bank of the Akutagawa River. The main enclosure is located on the ridge summit at an altitude of approximately 182.69 meters, with a relative height of approximately 80 meters from the southern foot of the mountain. Surrounded on three sides by the Akutagawa River valley (north, west, and south), it was a natural stronghold, making it extremely difficult to attack.
Main Enclosure and Eastern Enclosure
The central part of the castle consists of the main enclosure and the eastern enclosure. The main enclosure is located at the highest point of the castle and is believed to have housed the lord’s residence and administrative buildings. From the main enclosure, one could see the Osaka Plain, making it a strategically important location.
The eastern enclosure was located east of the main enclosure and functioned as an important defensive stronghold protecting the main enclosure. A dry moat was constructed between the two enclosures, a measure taken to prevent enemy intrusion.
Dry Moats and Earthen Bridges
A notable feature of Akutagawayama Castle is the numerous dry moats (horikiri). A dry moat is a dry ditch dug across a ridge, serving as a defensive structure to prevent enemy intrusion. At Akutagawayama Castle, multiple dry moats are located between the main enclosure and each of the enclosures, showcasing a typical defensive system of a mountain castle from the Sengoku period.
Earthen bridges (dobashi) are also found spanning some of the dry moats. These earthen bridges were used to cross the moats, serving as passageways in peacetime and as structures that could be destroyed in times of conflict to halt enemy advances.
Vertical Earthworks and Stone Walls
Vertical earthworks (tatedorui) are earthen ramparts built vertically along slopes, serving as defensive structures to prevent enemies from climbing the slopes. At Akutagawayama Castle, vertical earthworks are constructed along the main approach routes, suggesting a meticulous defensive plan for siege warfare.
Some stone walls remain, providing valuable evidence of castle construction techniques from the late Sengoku period. They are not entirely stone walls, but rather feature a distinctive structure combining earthworks and stone.
Enclosures
In addition to the main enclosure and eastern enclosure, several other enclosures (kuruwa) are located within the castle grounds. Enclosures are flat areas within the castle, used as garrisons for soldiers and storage for supplies. At Akutagawayama Castle, various sizes of enclosures are arranged according to the terrain, demonstrating efficient use of space.
The Relationship Between Akutagawayama Castle and Akutagawa Castle (Flatland Castle)
When discussing Akutagawayama Castle, its relationship with the flatland castle built at the foot of the mountain in Tonomachi is crucial. Generally, the mountain castle built on Mount Miyoshi is called “Akutagawayama Castle,” while the flatland castle at the foot is called “Akutagawa Castle.”
It is believed that this formed a so-called “Negoya-style” castle system, where administrative affairs were conducted at Akutagawa Castle at the foot of the mountain during peacetime, and the Akutagawayama Castle on the mountaintop was used for siege during wartime. This combination of mountain and flatland castles is an important example illustrating the developmental stages of castles during the Sengoku period.
The castle town, known as Akutagawa-juku, was also developed and flourished as a center of politics, economy, and culture. During the time of Miyoshi Nagayoshi, cultural activities such as linked verse gatherings and tea ceremonies were held, and cultural activities were thriving.
Akutagawayama Castle as one of the Continued Top 100 Japanese Castles
In March 2017, Akutagawayama Castle was selected as one of the “Continued Top 100 Japanese Castles” by the Japan Castle Association. This is the second selection following the “Top 100 Japanese Castles” chosen in 2006, and features castles selected from among important castles throughout Japan.
The reasons for Akutagawayama Castle’s selection are as follows:
- One of the finest mountain castles of the Sengoku period: Its layout and remains are well-preserved, making it a highly academically valuable example of a typical Sengoku period mountain castle.
- Residence of Miyoshi Nagayoshi: As the base of operations for Miyoshi Nagayoshi, a “ruler of Japan” before Oda Nobunaga, it holds great historical importance.
- Function as a provincial governor’s residence: It served not merely as a military facility, but as a political center.
- Designated as a national historic site: Designated as a national historic site in November 2022, preservation and utilization efforts are underway.
Stamp Location
The stamp for the Continued Top 100 Japanese Castles is located at the following location:
Takatsuki City Shiroato History Museum
- Address: 1-7 Jonai-cho, Takatsuki City, Osaka Prefecture
- Opening Hours: 10:00-17:00 (Last entry at 16:30)
- Closed: Mondays (or the following weekday if Monday is a public holiday), New Year holidays
- Admission Fee: 200 yen for adults, 100 yen for elementary and junior high school students
The Shiroato History Museum also features exhibits related to Akutagawayama Castle, and visiting before your visit will deepen your understanding of the castle. Located adjacent to the Takatsuki Castle ruins, it offers a comprehensive learning experience about Takatsuki’s history.
Access and Visiting Akutagawayama Castle Ruins
Access Methods
Using Public Transportation
- Get off at JR Kyoto Line “Takatsuki Station” or Hankyu Kyoto Line “Takatsuki-shi Station”
- Take the Takatsuki City Bus bound for “Tsukawaki” and get off at the “Tsukawaki” bus stop (approx. 15 minutes)
- Walk approximately 10 minutes from the bus stop to the trailhead
- Walk approximately 30-40 minutes from the trailhead to the main enclosure
Using a Car
Approximately 20 minutes from Meishin Expressway “Ibaraki IC” via National Route 171. There is parking space near the trailhead, but the number of spaces is limited, so using public transportation is recommended.
Ascent Route
The main ascent routes to Akutagawayama Castle Ruins are as follows:
Settsukyo Course (Most Common)
- Time Required: Approximately 30-40 minutes ascent, approximately 25-30 minutes descent
- Difficulty: Intermediate (The trail is well-maintained, but there are steep sections)
- Highlights: Moats, earthworks, main enclosure, eastern enclosure
While the trail is well-maintained, as it is a mountain castle, a certain level of physical fitness and equipment is required. Please note the following:
- Wear comfortable clothing and hiking boots or trekking shoes
- Bring drinking water
- Bring insect repellent in summer
- Be careful as it can be slippery in rainy weather or after rain
- Allow ample time in winter as the sun sets early
Points of Interest
Main Enclosure (Honmaru)
This is the central part of the castle, located at the highest point. The view from here is magnificent, offering a panoramic view of the Osaka Plain. On a clear day, you can see the skyscrapers of Osaka City and even the Ikoma Mountains. An information board is installed in the main enclosure, where you can learn about the castle’s history and structure.
Moat System
The moats between the main enclosure and each of the other enclosures are important remains for understanding the defensive system of Akutagawayama Castle. The moats, several meters deep, cut across the ridge, demonstrating the high level of castle-building technology of the Sengoku period.
Vertical Earthworks
The vertical earthworks built along the slopes were a clever way to prevent enemy intrusion. They remain understand clearly visible today, allowing us to the defensive plan of the time.
Eastern Enclosure
This is an important enclosure located on the east side of the main enclosure. It functioned as a defensive base protecting the main enclosure.
Precautions for Visitors
- As the castle ruins are located in the mountains, it is recommended to visit in groups rather than alone.
- Please note that there are areas where cell phone signals are weak.
- To protect the remains, do not climb on the stone walls or earthworks.
-Please take all your trash with you.
- No open flames allowed.
- Beware of wild animals (wild boars, venomous snakes, etc.).
Preservation and Utilization Efforts by Takatsuki City
Takatsuki City is actively working to preserve and utilize the Akutagawayama Castle ruins. Following its designation as a National Historic Site in November 2022, the following activities are being carried out:
Preservation and Maintenance
- Surveying and recording of the remains
- Installation of explanatory and information boards
- Maintenance of hiking trails and safety measures
- Protection of remains through vegetation management
Public Awareness Activities
- Permanent exhibition at the Shiroato History Museum
- Holding of special and planned exhibitions
- Conducting on-site tours and guided tours
- Publication of feature articles in the city’s public relations magazine, “Takatsuki DAYS”
- Creation and distribution of brochures and leaflets
Digital Utilization
- Information dissemination on the Takatsuki City official website
- Consideration of restoring the castle’s appearance using VR and AR
- Information dissemination via social media
Akutagawayama Castle and Related Historic Sites
When visiting Akutagawayama Castle, a deeper understanding can be gained by also visiting the surrounding related historical sites.
Takatsuki Castle Ruins
This is a flatland castle that was renovated by Oda Nobunaga after the abandonment of Akutagawayama Castle. It was ruled by warlords such as Takayama Ukon and other daimyo known for their Christian faith. Currently, it is maintained as a castle ruins park, and the Castle Ruins History Museum stands there.
Iimoriyama Castle Ruins
This is a mountain castle where Miyoshi Nagayoshi moved his base from Akutagawayama Castle. Spanning Daito City and Shijonawate City in Osaka Prefecture, it is one of the largest mountain castle ruins in Osaka Prefecture, alongside Akutagawayama Castle. It has also been selected as one of the Continued Top 100 Japanese Castles.
Settsu Gorge
This gorge spreads north of Akutagawayama Castle and is known as a famous spot for cherry blossoms and autumn leaves. It also serves as an access route to the castle ruins, allowing visitors to enjoy nature while climbing.
Cultural Aspects of Miyoshi Nagayoshi and Akutagawayama Castle
Miyoshi Nagayoshi was known not only as a warlord but also as a cultural figure. Akutagawayama Castle frequently hosted linked verse (renga) gatherings and tea ceremonies, serving as a cultural center of the time.
Nagayoshi was fond of linked verse and invited renowned renga poets such as Satomura Jōha to hold poetry gatherings. He was also deeply knowledgeable about the tea ceremony and associated with tea masters such as Tsuda Sōgyū.
The cultural activities at Akutagawayama Castle were not merely entertainment but also had political significance. Through cultural events, he strengthened ties with his vassals and allies and used them as a means of demonstrating his authority.
Historical Significance of Akutagawayama Castle
Akutagawayama Castle holds the following important significance in the history of Japan’s Sengoku period:
Base for Controlling the Kinai Region
Located in the heart of Settsu Province, Akutagawayama Castle was a strategic point connecting Kyoto and Osaka, making it a crucial base for controlling the Kinai region. Controlling this castle meant political and military superiority in the Kinai region. ### Symbol of the Miyoshi Regime
This was the base of operations during the era when Miyoshi Nagayoshi reigned as “ruler of Japan,” and the center of the unified government before Oda Nobunaga. Nagayoshi’s political methods and power structure are believed to have influenced later figures such as Oda Nobunaga and Toyotomi Hideyoshi.
Transition Period from Mountain Castles to Flatland Castles
The castle system, combining Akutagawayama Castle and the flatland castle at its base, is an important example of the transition period from medieval mountain castles to early modern flatland castles. It is a valuable historical site for understanding the changes in castle architecture from the Sengoku period to the Azuchi-Momoyama period.
Castle Construction Techniques of the Late Sengoku Period
The remains of moats, vertical earthworks, and stone walls are valuable historical materials that convey the castle construction techniques of the late Sengoku period. They have high archaeological and architectural historical value.
Summary
Akutagawayama Castle, built by Hosokawa Takakuni and later serving as the residence of Miyoshi Nagayoshi during his time as a powerful ruler of Japan, is one of the most prominent mountain castles of the Sengoku period. Built on Mount Miyoshi (182.69 meters above sea level), it boasted a robust defensive system that utilized the natural terrain.
Selected as one of the Continued Top 100 Japanese Castles and designated a National Historic Site in 2022, the Akutagawayama Castle ruins still retain many well-preserved structures. Visiting the main enclosure, eastern enclosure, moats, earthworks, and stone walls allows visitors to experience the appearance of a Sengoku period mountain castle firsthand.
Takatsuki City is actively working on preservation and utilization efforts, offering various ways to learn about the history of Akutagawayama Castle, such as obtaining stamps at the Castle Ruins History Museum and participating in on-site tours.
With its panoramic views of the Osaka Plain, the lingering atmosphere of the Sengoku period, and the footsteps of Miyoshi Nagayoshi, a figure known as “the unifier of Japan,” Akutagawayama Castle is an essential historical site for understanding Japan’s Sengoku period. It’s a recommended spot not only for those touring the Continued Top 100 Castles of Japan, but also powerful for history buffs and hiking enthusiasts. Be sure to visit this classic romantic mountain castle at at least once.
