Usuki Castle: A Complete Guide to its History and Highlights | The Castle of Otomo Sorin, Transformed from a Seaside Fortress to a Cherry Blossom Viewing Spot
Located in Usuki City, Oita Prefecture, Usuki Castle is a seaside fortress built during the Sengoku period by Otomo Sorin, a daimyo known for his Christian faith. Originally built on Nyu Island in Usuki Bay, it functioned as a natural stronghold surrounded by the sea on all sides. Currently, it has been reclaimed and connected to the mainland, becoming Usuki Park, a popular recreational area for citizens and a beloved cherry blossom viewing spot.
Table of Contents
- Overview and Alternate Names of Usuki Castle
- Sengoku Period: Construction by Otomo Sorin
- Early Modern Period: Usuki Domain during the Edo Period
- Castle Structure and Characteristics of Stone Walls
- Keep and Existing Structures
- Changes Since the Meiji Era
- Current Usuki Castle Ruins (Usuki Park)
- Access and Tourist Information
- Works Related to Usuki Castle
Overview and Alternate Names of Usuki Castle
Usuki Castle was a Japanese castle located in Usuki City, Oita Prefecture. The castle ruins are designated as a national historic site. This castle was also known as “Niujima Castle” and “Kijo Castle,” and was a unique sea castle built on Niujima, an isolated island in Usuki Bay.
Nyuujima Island measured approximately 420 meters east-west and 100 meters north-south, and had a cliff-like topography surrounded by the sea on three sides: north, east, and south. With a height of about 15 meters above sea level, it was a formidable, isolated island surrounded by bedrock, making it extremely difficult to attack.
Its alternative name, “Kamejo” (Turtle Castle), is said to originate from the island’s shape resembling a turtle. This location was the primary reason why Usuki Castle continued to function as an important base from the Sengoku period through to the Edo period.
Sengoku Period: Construction by Otomo Sorin
Construction in Eiroku 5 (1562)
The history of Usuki Castle begins in Eiroku 5 (1562), when Otomo Sorin, known as a Christian daimyo, built it as Nyuujima Castle. The Otomo clan was a Sengoku period daimyo (feudal lord) based in Bungo Province (present-day Oita Prefecture). During the time of Sorin, they had established a vast sphere of influence in northern Kyushu.
The reason Otomo Sorin chose Nyu Island in Usuki Bay as the site for his castle was clear. Nyu Island possessed a geographical characteristic: it was only accessible by land at low tide, and at high tide, one had to cross the sea to reach it. This natural fortification was deemed ideal for a defensive base in the context of the Sengoku period.
Center of Christian Culture
Otomo Sorin was a devout Christian daimyo, and traces of his faith remain strongly evident at Usuki Castle. A place of worship was established within the castle, and a Christian seminary was built in the town below.
Of particular note are the alphabet-like characters carved into the stone walls. These markings are thought to be either evidence of work by Christian stonemasons or an expression of faith, conveying to this day that Usuki Castle was an important center of Christian culture.
As a Base of the Otomo Clan
Usuki Castle served as the residence of Otomo Sorin and became the political and military center of the Otomo clan. Sorin moved his base from Funai (present-day Oita City) to Usuki, and used this coastal castle as a base to maintain his power in Kyushu.
Even after the crushing defeat at the hands of the Shimazu clan in the Battle of Mimikawa in 1578, the strong defenses of Usuki Castle continued to protect the Otomo clan. In 1586, the castle was subjected to a large-scale attack by the Shimazu clan, but its geographical advantage as a coastal castle and reinforcements from Toyotomi Hideyoshi prevented its fall.
Early Modern Period: Usuki Domain during the Edo War
The Era of Fukuhara Naotaka and Ota Kazuyoshi
After the Battle of Sekigahara, when the Otomo clan was dispossessed of their domain, new lords took control of Usuki Castle. In 1600 (Keicho 5), Fukuhara Naotaka was appointed with a 60,000 koku stipend, followed by Ota Kazuyoshi in 1602 (Keicho 7) with a 65,000 koku stipend.
During this period, improvements were made to the castle’s fortifications. Especially during the time of the Fukuhara and Ota clans, land reclamation began in the area across the river known as “Gionsu,” and the third bailey was constructed. This expanded the castle’s size and laid the foundation for the development of the castle town.
The 15-Generation Rule of the Inaba Clan
In 1614 (Keicho 19), Inaba Sadamichi was appointed to the domain with a 50,000 koku stipend. From then until the Meiji Restoration, 15 generations of the Inaba clan ruled as lords of the Usuki Domain. The long rule of the Inaba clan greatly contributed to the development of Usuki town and culture.
During the Inaba era, the castle’s fortifications were further improved, completing the layout consisting of the main keep, second bailey, and third bailey. The castle town was also developed, and commerce and culture flourished. Although a small domain with a 50,000 koku stipend, the Usuki Domain focused on education and culture, producing many outstanding individuals.
Throughout the Edo period, Usuki Castle continued to function as the domain’s administrative center, and the surrounding sea provided natural protection. It enjoyed a period of peace until the end of the Edo period, without being struck by major warfare.
Castle Structure and Stone Wall Characteristics
Honmaru and Ninomaru
The core of Usuki Castle consists of the Honmaru and Ninomaru, built on Niu Island. The Honmaru was located at the highest point of the island, surrounded by the Ninomaru. Both the Honmaru and Ninomaru were surrounded by steep cliffs on all four sides, making intrusion from the sea difficult.
The Honmaru housed the lord’s residence and government offices, functioning as the center of domain administration. The Ninomaru contained the residences of senior retainers and various facilities, supporting the castle’s defense and operation.
Sannomaru and Gion-shu
The Sannomaru was built on Gion-shu, which was reclaimed during the time of the Fukuhara and Ota clans. The Sannomaru was connected to the island containing the Honmaru and Ninomaru by a bridge, functioning as the castle’s outer defense. The residences of retainers and samurai quarters were located here, serving as a point of contact with the castle town.
Characteristics and Markings of the Stone Walls
The stone walls of Usuki Castle are noteworthy for their technical value and cultural characteristics. Built from the Sengoku period to the early Edo period, the walls showcase various castle-building techniques from different eras.
Particularly interesting are the characters and symbols carved into the stone walls. As mentioned earlier, markings resembling the alphabet can be seen, which are considered valuable relics indicating the influence of Christian culture during the time of Otomo Sorin. Markings indicating the stonemasons and builders also remain, making them important resources for studying the castle-building techniques of the time.
The stone walls, utilizing the surrounding bedrock, have a robust structure that can withstand waves and wind and rain from the sea, and parts of them remain in good condition even today.
The Keep and Existing Structures
History of the Keep
Usuki Castle once had a keep. It is believed that a structure equivalent to a keep already existed during the time of Otomo Sorin, and a formal keep was built during the Edo period. However, due to the limited amount of remaining historical documents, the detailed structure and scale of the castle remain unclear.
The castle tower was demolished during the Meiji era due to the castle demolition decree, and only the stone foundation remains today. From this foundation, one can enjoy a panoramic view of Usuki town and Usuki Bay, truly appreciating the magnificent location of the castle as a coastal fortress.
Existing Turrets
Some Edo period structures still exist at Usuki Castle. Particularly important are the Tatami Turret and the Utoraguchi Gateside Turret.
The Tatami Turret is a two-story turret and one of the valuable structures still standing at Usuki Castle. Along with the Utoraguchi Gateside Turret, it preserves the appearance of Edo period castle architecture. These turrets are preserved as important cultural properties that demonstrate the historical value of Usuki Castle.
Restored Ote Yagura Gate
In recent years, Usuki Castle has also undergone the restoration of historical buildings. The Ote Yagura Gate has been restored, allowing visitors to imagine the former grandeur of the castle.
The restoration aimed for the most historically accurate reproduction possible, based on ancient documents, drawings, and archaeological findings. This Ote Yagura Gate is an important structure that allows visitors to the Usuki Castle ruins to experience the appearance of the castle during the Edo period.
Changes After the Meiji Era
Abolition of the Castle and Land Reclamation
After the Meiji Restoration, the Usuki Domain was abolished in 1871 (Meiji 4) with the abolition of the feudal domains and establishment of prefectures, and Usuki Castle ceased to exist. In 1873 (Meiji 6), the castle was officially abolished by the Castle Abolition Order, and many buildings were demolished.
A further significant change was the reclamation of the surrounding sea. In the Meiji era, land reclamation around Nyu Island intensified, and the island castle, once surrounded by the sea, gradually became connected to the mainland. This reclamation expanded Usuki’s urban area, leading to its development into a modern town.
Designation and Preservation of the Historic Site
Recognized for the historical value of Usuki Castle ruins, preservation efforts were initiated. Currently, Usuki Castle ruins are designated as a national historic site and protected as an important cultural property.
The remains, such as stone walls and turrets, are appropriately preserved and managed as cultural properties, and archaeological excavations are continuously conducted. These investigations are revealing new insights into the castle’s structure and history.
Current Usuki Castle Ruins (Usuki Park)
As a Cherry Blossom Viewing Spot
Currently, Usuki Castle ruins have been developed into Usuki Park, a place of relaxation for citizens. It is particularly known as a cherry blossom viewing spot in spring, with numerous cherry trees planted throughout the castle grounds.
During cherry blossom season, the full bloom of cherry blossoms adorns the stone walls and turrets, attracting many visitors. At night, the trees are illuminated, allowing visitors to enjoy the magical sight of cherry blossoms after dark. This former seaside castle is now a beloved cherry blossom viewing spot for the locals.
Park Facilities
Usuki Park features a sports field, a playground, and a shrine. From the elevated castle ruins, visitors can enjoy panoramic views of Usuki town and Usuki Bay, making the scenery a major draw.
Walking paths are also maintained, allowing visitors to reflect on history while exploring the stone walls and turrets. Information boards are placed throughout the grounds, providing insights into the history and structure of Usuki Castle.
As a Tourist Hub
Usuki Castle Ruins is one of Usuki City’s main tourist attractions. Along with the townscape of Usuki, which retains the atmosphere of a castle town, it attracts many tourists.
The Usuki City Tourism Association and other organizations have developed tourist routes including the Usuki Castle ruins and are disseminating information, functioning as a hub for conveying the charm of Usuki, a town rich in history and culture.
Access and Tourist Information
Location and Access
Usuki Castle Ruins (Usuki Park) is located in Usuki, Usuki City, Oita Prefecture. It is easily accessible, approximately a 10-minute walk from Usuki Station on the JR Nippo Main Line. By car, it is approximately 10 minutes from the Usuki Interchange on the Higashi-Kyushu Expressway.
Parking is available around the park, making it convenient to visit by car. Because it is located in the Usuki city center, it can be visited in conjunction with a stroll through the castle town.
Points to Note When visiting Usuki Castle Ruins, paying attention to the following points will enhance your experience:
- Inscriptions on the Stone Walls: Look for the alphabet-like inscriptions that indicate traces of Christian culture.
- Existing Turrets: Observe the Edo period architecture of the Tatami Turret and the Utora-guchi Gateside Turret up close.
- View from the Castle Tower: The view of Usuki town and Usuki Bay is a must-see.
- Restored Ote-yagura Gate: Experience the grandeur of the former castle.
- Imagining the Former Coastline: Although it is now connected to the mainland, it is interesting to stroll around while imagining that it was once an island.
Nearby Tourist Attractions
There are many other sights to see around Usuki Castle Ruins:
- Usuki Stone Buddhas: A group of rock-carved Buddhas designated as a National Treasure.
- Usuki Castle Town: A historical townscape with samurai residences and merchant houses remaining.
- Nioza Historical Road: A beautiful historical street with cobblestones.
- Former Shinkoji Temple: A temple associated with a Christian daimyo.
By combining these, you can enjoy a sightseeing route that fully showcases Usuki’s history and culture.
Works Related to Usuki Castle
There are also works that feature Usuki Castle and Otomo Sorin. Historical novels and dramas depict the life of Otomo Sorin as a Christian daimyo during the Sengoku period, and stories set at Usuki Castle.
Locally, there are museums and exhibition facilities introducing the history of Usuki Castle, where you can learn more about it. The Usuki City Tourism Association also provides brochures and guidebooks about Usuki Castle.
Summary
Usuki Castle is a unique castle with a distinctive history and culture, built during the Sengoku period by the Christian daimyo Otomo Sorin. Constructed on the naturally fortified island of Nyuu in Usuki Bay, it boasted a strong defense surrounded by the sea.
During the Edo period, the Inaba clan ruled for 15 generations, and it functioned as the administrative center of the Usuki Domain, a 50,000-koku domain. After the Meiji Restoration, the surrounding area was reclaimed and connected to the mainland, losing its former island castle appearance. However, remnants such as stone walls and turrets remain.
Currently, it is maintained as Usuki Park, a popular cherry blossom viewing spot for citizens, and is preserved as a national historical site. The alphabet-like inscriptions carved into the stone walls are valuable traces of Christian culture, conveying the unique history of Usuki Castle to the present day.
When you visit Usuki, be sure to stop by the Usuki Castle ruins and experience both its history as a coastal castle and its current charm as a famous cherry blossom viewing spot. As you stroll around, imagining the remnants of the island castle once surrounded by the sea, you will be able to feel the history of Usuki Castle more deeply.
