Hiyama Castle (Akita Prefecture) Complete Guide: A Famous Castle in Northern Akita Built by the Ando Clan, the Generals of Japan
What is Hiyama Castle?
Hiyama Castle is a medieval mountain castle built on Kiriyama, a hill approximately 120 meters above sea level, on the eastern side of the Hiyama district in Noshiro City, Akita Prefecture. From the mid-Muromachi period to the Sengoku period, it served as the base of the Hiyama Ando clan, who ruled the northern part of Akita Prefecture, and was the political and military center of the Noshiro-Yamamoto region for over 400 years.
The castle grounds boast a vast scale, measuring 1500 meters east-west and 900 meters north-south, and are known as an Ezo-style horseshoe-shaped mountain castle. Also known as “Kiriyama Castle” and “Horinouchi Castle,” the site, including the Hiyama Castle ruins and the surrounding areas of Odachi, Chausukan, and Kokuseiji Temple, was designated a National Historic Site in 1980 (Showa 55) and 1986 (Showa 61) as the “Hiyama Ando Clan Castle Site.”
History of the Hiyama Ando Clan
Establishment of the Ando Clan and Expansion into Hiyama
The Ando clan was a powerful local family that wielded considerable influence in northern Akita Prefecture during the medieval period. While there are various theories regarding their origins, they are said to be descendants of the Abe clan or descendants of Fujiwara no Hidesato. From the Kamakura period to the Muromachi period, they expanded their power in the Tsugaru and Akita regions along the Sea of Japan, establishing their economic base by monopolizing trade with Ezo (Hokkaido).
It is believed that Ando Kanesue built a castle in Hiyama in the mid-14th century, and that Hiyama Castle was completed around 1495 by Ando Tadasue. During this period, the Ando clan was divided into the Minato Ando and Hiyama Ando clans, but the Hiyama Ando clan rose to prominence as the major power in the northern Ushino region.
The Era of Ando Chikasue: Reaching its Peak
Hiyama Castle reached its peak during the reign of Ando Chikasue (1539-1587), the 8th head of the Hiyama Ando clan. With his exceptional military talent and political acumen, Chikasue controlled a vast territory stretching from northern Akita Prefecture to southern Aomori Prefecture. His power was so great that he was called the “Shogun of Japan,” and he was able to contend on equal footing with surrounding Sengoku daimyo such as Mogami Yoshiaki and the Nanbu clan.
Aiki expanded his territory through aggressive military actions, becoming the most powerful force in northern Dewa Province. However, in 1587, he died of illness in his camp during a battle with Tozawa Moriyasu, the lord of Kakunodate Castle. His sudden death at the age of 49, in the prime of his life, was a major blow to the Hiyama Ando clan.
The Battle of Minato (Minato Rebellion) and the Siege of Hiyama Castle
After Aiki’s death, his second son, Ando Sanesue, only 12 years old, inherited the family headship. However, Ando Michisue (also known as Toyoshima Michisue), a member of the family dissatisfied with the rise of a young head, launched a rebellion. This is the internal family conflict known as the “Battle of Minato” or “Minato Rebellion.”
In this conflict, which began in 1589, Sanesue holed up in Hiyama Castle and faced the forces of the Minato Ando clan led by Michisue. The siege lasted for over five months, but despite his youth, Sanesue defended the castle successfully, ultimately achieving victory with the support of Akita Sanesue (later known as the Akita clan), a Sengoku daimyo of Akita. This siege is known as a historical event demonstrating the formidable strength of Hiyama Castle.
The Battle of Sekigahara and the End of Hiyama Castle
After winning the Battle of Minato, Ando Sanesue continued to manage his domain from Hiyama Castle. However, in the Battle of Sekigahara in 1600, Sanesue sided with the Eastern Army, and as a reward for his service after the war, he was transferred to Shishido in Hitachi Province with a 50,000 koku stipend. This led to the abandonment of Hiyama Castle, marking the end of the era of the Hiyama Ando clan.
Subsequently, northern Akita Prefecture came under the control of the Satake clan, and the Hiyama region also became part of their territory. Hiyama Castle was left unused and abandoned, eventually becoming buried in the forest.
Structure and Layout of Hiyama Castle
Overall View of the Castle Area
Hiyama Castle was a large mountain castle built on the ridge of Mt. Kiriyama, with a castle area extending 1500 meters east-west and 900 meters north-south. It is characterized by its Ezo-style horseshoe-shaped layout, skillfully utilizing the terrain, and a complex arrangement of baileys and defensive structures have been confirmed.
The Ushu Kaido road ran through the western side of the castle, giving it a strategic location controlling a key transportation hub. Furthermore, the Hiyama River flowed north of the castle, serving as a natural moat.
Major Enclosures and Remains
Hiyama Castle features multiple enclosures, arranged in a stepped pattern around the main enclosure. The following remains can still be observed today:
Main Enclosure (Honmaru): Located in the center of the castle, built on the highest elevation. It is presumed that the lord’s residence was located here.
Second and Third Enclosures: A group of enclosures surrounding the main enclosure, serving as a crucial defensive structure.
Moat: A defensive structure built to divide the ridge, playing a vital role in preventing enemy incursions. Multiple moats have been identified at Hiyama Castle, and their large scale indicates the castle’s high defensive capabilities.
Earthwork: Earthen walls built around the enclosures, serving to protect against enemy attacks. Some parts remain in good condition today.
Vertical Moat: A moat dug along the slope, serving to prevent enemy flanking attacks and also providing drainage.
Subsidiary Castles and Castle Complex
To strengthen the defenses of Hiyama Castle, several subsidiary castles were strategically located in the surrounding area.
Chausu Castle Ruins: A subsidiary castle located southeast of Hiyama Castle, it formed part of the castle’s defensive line. Remains of earthworks and baileys still exist today.
Odachi Castle Ruins: Located northwest of Hiyama Castle, it is believed to have served to monitor the Ushu Highway.
Kokuseiji Temple Ruins: The site of the Hiyama Ando clan’s family temple, which functioned as part of the castle complex. It is presumed to have served not only as a temple but also as a defensive base in emergencies.
These subsidiary castles and castle complexes constitute a comprehensive defensive system centered around Hiyama Castle and are collectively designated as a National Historic Site under the name “Hiyama Ando Clan Castle Complex Ruins.”
Highlights of Hiyama Castle
Large-Scale Moat
The most impressive feature of Hiyama Castle is the large-scale moat that cuts through the ridge. The moat, several meters deep, demonstrates the advanced civil engineering techniques of the time and speaks to the castle’s strong defenses. Standing at the bottom of the moat, you can feel the imposing presence of the earthen walls rising on both sides.
Layout of the Enclosures
The group of enclosures, continuous from the main enclosure, are arranged in a stepped pattern, showcasing the skillful design of the fortifications. Earthen ramparts remain in each enclosure, allowing us to imagine the castle’s structure at the time. The enclosures around the main enclosure are particularly well-preserved, offering a glimpse into the typical form of a medieval mountain castle.
Views
From near the main enclosure, you can enjoy a panoramic view of the Noshiro Plain, and on clear days, even the Sea of Japan. This excellent view was also important for military surveillance, and is thought to be one of the reasons why the Ando clan chose this location as their base.
Harmony with Nature
The current Hiyama Castle ruins are surrounded by abundant nature. In spring, the fresh greenery is beautiful, and in autumn, the autumn leaves are stunning. Visitors can enjoy nature along with a historical stroll. The landscape, where the ruins and nature harmonize, evokes a medieval atmosphere for visitors.
Access Information
Access by Car
From the Akita Expressway: Approximately 15 minutes by car from Noshiro Minami IC. Head north on National Route 7 towards the Hiyama area.
Parking: Free parking is available at the foot of the Hiyama Castle ruins. However, spaces are limited, so caution is advised during busy times.
Access by Public Transportation
JR Ou Main Line: Takanosu Station or Futatsui Station are the nearest stations. From the stations, it’s approximately 15-20 minutes by taxi.
Route Bus: There are buses from Noshiro city center towards Hiyama, but the number of buses is limited, so it’s necessary to check the timetable in advance.
Access by public transport is somewhat inconvenient, so we recommend renting a car or arranging a taxi.
Notes on Visiting the Castle
Estimated Time Required: It takes approximately 30-40 minutes on foot from the foot of the mountain to the main enclosure. Including sightseeing time, allow about 1.5 to 2 hours in total.
Clothing and Equipment: As it is a mountain castle, comfortable walking shoes and clothing are essential. In summer, bring insect repellent and drinking water. In winter, climbing may be difficult due to snow.
Safety: To protect the remains, please do not enter restricted areas. Also, some parts of the mountain path are slippery, so please watch your step as you climb.
Nearby Tourist Attractions
Noshiro City Local History Museum
This facility houses materials related to the Hiyama Ando clan and allows you to learn about the history of the Noshiro region. Visiting before visiting Hiyama Castle will give you a deeper understanding of the castle’s history.
Noshiro Energiam Park
A science museum attached to the Noshiro Thermal Power Plant, this facility offers a fun way to learn about energy. Recommended for families.
Kimimachizaka Prefectural Natural Park
A scenic spot near JR Futatsui Station, where you can enjoy the beauty of the Yoneshiro River gorge. It is especially beautiful during the autumn foliage season, attracting many tourists.
Shirakami Mountains
The Shirakami Mountains, a World Natural Heritage site, is about an hour’s drive from Noshiro City. You can experience the magnificent nature of the vast primeval beech forests.
The Cultural Value of Hiyama Castle
Significance as a National Historic Site
The Hiyama Ando Clan Castle Ruins possess extremely high historical value as a group of castles belonging to a powerful local clan in northern Tohoku during the medieval period. In particular, as the base of the Ando clan, who prospered through trade with Ezo (Hokkaido), and a crucial hub connecting the northern world with Honshu, this site is indispensable for understanding Japanese medieval history.
Preservation and Utilization
Noshiro City is actively working on the preservation and utilization of the Hiyama Ando Clan Castle Site. In addition to the preservation and management of the remains, efforts are being made to create a safe environment for visitors, including the installation of information boards and the development of walking paths.
Furthermore, local history enthusiasts and citizen groups are conducting cleaning activities and research, ensuring that the site is carefully protected as a regional treasure.
Future Investigations and Research
Ongoing archaeological investigations are currently being conducted at the Hiyama Castle site. Excavations have yielded new insights into the lifestyle of the time and the structure of the castle, and it is expected that a more detailed picture of the castle will be revealed in the future.
Summary
Hiyama Castle played a significant role in the history of northern Akita Prefecture as the residence of the Hiyama Ando clan, which produced Ando Yoshisue, known as the “Shogun of Japan” during the Sengoku period. It was a large-scale mountain castle with a vast area measuring 1500 meters east-west and 900 meters north-south, and its remains are still well-preserved.
During the siege of the Battle of Minato, the young Ando Sanesue defended the castle for over five months, proving its formidable strength. Currently designated as a national historic site, it is recognized for its high historical value as a group of castles belonging to a powerful local clan in northern Tohoku during the medieval period.
When visiting Noshiro City, be sure to visit the Hiyama Castle ruins and trace the footsteps of the Ando clan who ruled northern Akita during the Sengoku period. The large moats, baileys, and views from the main enclosure will allow visitors to feel the spirit of the medieval era. This historical site is recommended not only for history buffs, but also for those who love mountain castles and those who enjoy nature walks.
