Tatsunokuchi Castle (Goto City, Nagasaki Prefecture): History and Highlights | A Flatland Castle Ruins Telling the Story of the Goto Islands’ Sengoku Period
Located in Kami-Otsu-cho, Goto City, Nagasaki Prefecture, Tatsunokuchi Castle is an important historical site that tells the story of the Goto Islands’ complex Sengoku period history. Built as a flatland castle facing the sea, it became the stage for the conflict between the Uku and Goto clans over control of the Goto Islands, leaving a significant mark on the region’s history. This article provides a detailed overview of Tatsunokuchi Castle, including its historical background, castle structure, local highlights, and access information.
Basic Information on Tatsunokuchi Castle
Location: Kami-Otsu-cho, Goto City, Nagasaki Prefecture
Castle Classification: Flatland Castle
Construction Period: Sengoku Period (Warring States Period)
Builder: Estimated to be related to the Uku clan
Main Lords: Uku clan, Goto clan
Remains: Remains of baileys, earthworks (partial)
Designated Cultural Property: None
Tatsunokuchi Castle is a flatland castle built near the coast of Kami-Otsu-cho, in the northeastern part of Fukue Island in the Goto Islands. The Goto Islands have long been a strategic point for trade with the continent, and during the Sengoku period, it was a fierce battleground where powerful local clans vied for supremacy. Tatsunokuchi Castle is one of the castles that played a military and politically important role within this historical context.
History of Tatsunokuchi Castle
Background of the Sengoku Period in the Goto Islands
The Sengoku period in the Goto Islands is characterized by the conflict between two powerful local clans: the Uku clan and the Goto clan (later the Goto clan). The Uku clan was originally based on Ojika Island and was a prominent family that had existed since the Heian period. The Goto clan, on the other hand, expanded its power mainly on Fukue Island.
From the 15th to the 16th centuries, the two clans fiercely clashed over control of the Goto Islands. This conflict was not merely a regional dispute, but a complex one involving relations with daimyo powers on the Kyushu mainland and pirate groups (Wako).
Construction and Role of Tatsunokuchi Castle
The exact date of Tatsunokuchi Castle’s construction is not clear from historical records, but it is estimated to have been during the mid-to-late Sengoku period. Based on the castle’s location, it is thought to have played the following roles:
- Maritime Traffic Monitoring Base: Located near the coastline of Kami-Otsu Town, it served to monitor ship traffic.
- Supply Base: A base for military operations in northern Fukue Island.
- Symbol of Territorial Control: A political symbol indicating that the Uku or Goto clan controlled the area.
Position in the Conflict Between the Uku and Goto Clan
Tatsunokuchi Castle was located in an area where the powers of the Uku and Goto clans were evenly matched. Northern Fukue Island was the border zone between the two forces, and Tatsunokuchi Castle became an important military base in the struggle for control of this region.
In the latter half of the 16th century, the Goto clan gradually gained the upper hand and eventually succeeded in unifying the entire Goto Islands. Further research is needed to determine what role Tatsunokuchi Castle played in this process and when it was abandoned.
After the Edo Period
In the Edo period, the Goto clan was officially recognized as the Fukue Domain and made Ishida Castle (Fukue Castle) their residence. Tatsunokuchi Castle is believed to have ended its military role and been abandoned with the end of the Sengoku period (Warring States period). Afterward, the site was used for farmland and residential areas, and remains so to this day.
Layout and Structure of Tatsunokuchi Castle
Characteristics as a Flatland Castle
Tatsunokuchi Castle is classified as a flatland castle. A flatland castle is a fortress built on flat or low-lying land, and has the following characteristics compared to mountain castles and hill castles:
- High Habitability: Due to the flat terrain, the construction of residences and barracks was easy.
- Convenient Material Transport: Close to the sea and rivers, making it easy to transport materials.
- Defensive Features: Due to the lack of natural fortifications, artificial defensive structures such as moats and earthworks were important.
In the case of Tatsunokuchi Castle, it is presumed that the design prioritized access from the sea, taking advantage of its location near the coast.
Existing Remains
Currently, the following remains are believed to partially survive at the Tatsunokuchi Castle site.
Kuruwa (Enclosure) Remains: The flat area that formed the center of the castle can be identified as a geographical feature. Much of it is now privately owned land or farmland, making the clear boundaries unclear.
Earthwork Remains: Some slightly elevated areas, possibly remnants of earthworks, may remain. However, due to years of development and agricultural land consolidation, only limited portions retain their original form.
Moat Remains: As it was a flatland castle, it’s possible that a water moat or dry moat existed in the past, but these are now filled in or altered.
Estimated Castle Area
While it’s difficult to pinpoint the exact castle area, based on the topography, place names, and surrounding land use, it’s estimated to have been approximately 100 meters east-west and 150 meters north-south. This is a standard size for a local powerful family’s residence or castle from the medieval to Sengoku period.
Highlights of Tatsunokuchi Castle
Imagining the Historical Landscape
The greatest appeal of visiting the Tatsunokuchi Castle ruins is imagining the historical drama that unfolded here. Although it is now a quiet residential area and farmland, during the Sengoku period (Warring States period), a castle was built here, samurai were stationed there, and it functioned as a strategic base that determined the fate of the Goto Islands.
Looking out at the coastline, you can imagine the ships that traveled in those days and the watchtowers that monitored maritime traffic.
Surrounding Historical Context
When visiting Tatsunokuchi Castle, a deeper understanding can be gained by visiting other historical sites in the Goto Islands.
Ishida Castle (Fukue Castle): An Edo period castle located in the center of Goto City. It was the final residence of the Goto clan and is valuable as one of the last castle buildings in Japan.
Dozaki Church: An important church building that tells the history of Christianity in the Goto Islands. The history of Goto is deeply intertwined not only with the samurai culture of the Sengoku period but also with the history of hidden Christians.
Ukujima Island: The base of the Uku clan. Located in the northern part of the Goto Islands, its geographical relationship with Tatsunokuchi Castle can be understood by comparing it to the castle itself.
Local Natural Environment
The area around Kami-Otsu Town boasts a beautiful coastline and abundant nature characteristic of the Goto Islands. Enjoying the nature of Goto, along with exploring the castle ruins, is a highlight of the trip. The clear waters, the complex topography of the ria coast, and the vegetation nurtured by the warm climate create a landscape unique to the Goto Islands.
Access to Tatsunokuchi Castle
Access to Goto City
Airplane: Approximately 30 minutes from Nagasaki Airport to Goto Tsubaki Airport. There are also direct flights from Fukuoka Airport (approximately 40 minutes).
Ferry: Ferry or high-speed boat from Nagasaki Port to Fukue Port. The ferry takes approximately 3 hours, while the high-speed boat (jetfoil) takes approximately 1 hour and 25 minutes.
Getting to Tatsunokuchi Castle Ruins from Goto City
By Car: From Fukue Port, head north on National Route 384 towards Kami-Otsu Town. Approximately 20 minutes. Renting a car is the most convenient option.
By Bus: Goto Bus operates local buses, but the number of services is limited, so it is recommended to check the timetable in advance.
By Taxi: Approximately 20 minutes by taxi from Fukue city center. Since arranging a return taxi may be difficult, consider chartering a taxi for both the outward and return journeys.
Important Notes at the Site
- Respect for Private Property: Much of the castle ruins are on private property. Please be careful not to trespass.
- Protection of Remains: Please view the site carefully, taking care not to damage the remaining earthworks or terrain.
- Lack of Information Boards: Detailed information boards may not be installed at Tatsunokuchi Castle Ruins. It is recommended to prepare reference materials in advance.
- Preparing for the Weather: It can be windy near the coast on some days. Please pay attention to your clothing and equipment.
Other Castle Sites in Goto City
Besides Tatsunokuchi Castle, there are several other castle sites in Goto City.
Ishida Castle (Fukue Castle)
A representative castle of Goto City, it is one of the last castles built in Japan during the late Edo period (1863). It features characteristics of a coastal castle facing the sea, and its stone walls and moats are well-preserved. It is designated as a national historic site along with the Goto Clan Garden, and is a must-see.
Egawa Castle Ruins
A mountain castle located in the central part of Fukue Island, it is considered one of the early bases of the Goto clan. The view from the mountaintop is magnificent, allowing you to appreciate its military importance at the time.
Daihoji Castle Ruins
A castle site remaining in Tamanoura-cho, Goto City, it was one of the branch castles of the Goto clan. Located on a hill overlooking the sea, this is an interesting historical site as a typical example of a castle built by a local powerful family during the Sengoku period (Warring States period).
To learn more about the history of the Goto Islands
Goto City Library
This library has a wealth of materials related to the history of Goto City. In the local history section, you can view documents related to the Goto and Uku clans, as well as research materials on castles.
Fukue Castle Goto Clan Garden (Shinji-ga-ike Pond)
Adjacent to Ishida Castle, the Goto Clan Garden features exhibits introducing the history and culture of the Goto Domain. You can learn about the history of Goto after the abandonment of Tatsunokuchi Castle.
Goto Tourism and History Museum
This facility allows you to learn about the history of the Goto Islands in general, with exhibits covering Goto’s history from ancient times to the modern era. The exhibit on the Sengoku period also explains the conflict between the Uku and Goto clans.
The Importance of Understanding the Sengoku Period History of the Goto Islands
Small, local castles like Tatsunokuchi Castle may seem unassuming compared to famous castles with large keeps and stone walls. However, these castles are precisely the invaluable historical sites that concretely tell the story of the region’s history.
The Sengoku period in the Goto Islands was not simply a series of skirmishes on the frontier of Kyushu. As a strategically important location facing the East China Sea, it unfolded a complex history involving international elements such as trade with the continent, the activities of Wokou (Japanese pirates), and the arrival of Christianity. Tatsunokuchi Castle is a precious witness that conveys a part of this history to the present day.
Sample Sightseeing Plan for Visiting Goto City
Here is an example of a historical exploration plan for Goto City, including the Tatsunokuchi Castle ruins.
Day 1
- Morning: Arrive at Fukue Port, visit Ishida Castle and Goto Clan Garden
- Afternoon: Stroll through Fukue city, visit Samurai Residence Street
- Evening: Check into accommodation
Day 2
- Morning: Visit Tatsunokuchi Castle Ruins, stroll around Kami-Otsu Town
- Afternoon: Visit Christian historical sites in Goto, including Dozaki Church
- Evening: Enjoy the natural scenery of Goto, including Osezaki Lighthouse
Day 3
- Morning: Visit Egawa Castle Ruins or Daihoji Castle Ruins
- Afternoon: Depart from Fukue Port
This plan allows you to enjoy Christian historical sites and natural scenery while touring the Sengoku period historical sites of Goto, centered around Tatsunokuchi Castle.
Current Status and Challenges of Tatsunokuchi Castle Research
Unfortunately, academic research on Tatsunokuchi Castle is not yet sufficiently advanced. The main challenges are as follows:
Lack of Historical Materials
Almost no contemporary historical documents describing Tatsunokuchi Castle remain. Even in documents from the Goto and Uku clans, direct descriptions of Tatsunokuchi Castle are limited. Therefore, even basic matters such as the construction period, the castle lord, and the date of abandonment must be relied upon as estimations.
Need for Archaeological Investigation
Because no archaeological excavations have been conducted at the castle site, the castle’s structure and size remain uncertain. Future academic surveys and excavations will likely shed more light on the true nature of Tatsunokuchi Castle.
Collaboration with Local History Research
To understand Tatsunokuchi Castle, research into the Sengoku period history of the entire Goto Islands, particularly the history of the conflict between the Uku and Goto clans, is essential. Organic collaboration with local history is required, not just research on the castle itself.
Message to Castle Enthusiasts
Tatsunokuchi Castle is a castle site where almost no visible remains such as stone walls or keeps remain. However, this is precisely what makes it so enjoyable to use your imagination. Reading the terrain and inferring its appearance from faint traces—this is surely the true joy of exploring castles.
While visiting famous castles is wonderful, visiting smaller, local castle ruins like Tatsunokuchi Castle allows you to truly appreciate the diversity and depth of Japanese castle culture. There are tens of thousands of castle ruins throughout Japan, most of which are “unassuming” castles like Tatsunokuchi Castle. However, each of these castles has its own unique history, imprinted with the lives of the local people.
Visiting the beautiful islands of the Goto archipelago and standing on the ruins of Tatsunokuchi Castle, gazing at the sea, and imagining the figures of samurai from the Sengoku period—such quiet moments are surely a blissful experience for history buffs.
Summary
Tatsunokuchi Castle is a Sengoku period flatland castle ruin located in Kami-Otsu-cho, Goto City, Nagasaki Prefecture, and is a valuable historical site that conveys the complex Sengoku history of the Goto Islands. This castle, believed to have played a crucial role in the conflict between the Uku and Goto clans, has few notable remains today, but it remains essential for understanding the history of Goto.
When visiting the Goto Islands, be sure to visit not only famous historical sites like Ishida Castle, but also smaller, more local castle ruins like Tatsunokuchi Castle. There, you’ll find a unique charm not found in larger castles, and the history of the region quietly breathes within. Enjoy a journey through the Goto Islands, blessed with beautiful seas and abundant nature, and let your imagination wander to the historical romance of the Sengoku period.
