Complete Guide to Torinji Castle (Ushiku City, Ibaraki Prefecture): A Thorough Explanation of the History and Remains of the Okami Clan’s Hilltop Castle
What is Torinji Castle?
Torinji Castle is a hilltop castle from the Sengoku period located at 149 Shinchi-cho, Ushiku City, Ibaraki Prefecture. Built by the Okami clan, who held power from Ushiku Castle, it played an important role as a subsidiary castle of Ushiku Castle. The castle measured approximately 150 meters north-south and 70 meters east-west, and boasts particularly well-preserved remains among the castle complexes around Ushiku Marsh.
Even today, the largest moat, earthworks, and baileys within the castle grounds remain in excellent condition, making it a valuable historical site for studying the structure of Sengoku period castles. It is a typical example of a medieval castle in Ibaraki Prefecture and attracts attention from castle researchers.
Basic Information on Torinji Castle
Location
149 Shinchi-cho, Ushiku City, Ibaraki Prefecture
Former Province
Hitachi Province
Classification/Structure
Hilltop Castle
Builder
Okami Clan
Construction Period
Estimated to be around the Eiroku era (1558-1570)
Main Lords
Okami Clan, later Kondo Clan
Remains
Dry moat, earthworks, baileys, outworks
Access
From Ushiku Station on the JR Joban Line, take the community bus and get off at “Mikazukibashi Lifelong Learning Center,” then walk for about 5 minutes.
Overview
Torinji Castle is a hilltop castle built on a plateau located on the southern shore of Ushiku Marsh. It is believed to have been built by the Okami clan, who were based at Ushiku Castle, to expand their power and strengthen their defenses. The castle’s location was a strategic point, backed by the natural fortification of Ushiku Marsh and offering panoramic views of the surrounding plains.
The castle grounds were extensive, measuring 150 meters north-south and 70 meters east-west, and featured a robust defensive system consisting of multiple baileys and deep dry moats. In particular, the largest moat within the castle grounds, located in front of the third bailey, is impressive in its depth and width.
The Okami clan formed a network of branch castles centered around Ushiku Castle, including Torinji Castle and Kosaka Castle, solidifying their power base in southern Hitachi Province. Torinji Castle held an important position within this network and is presumed to have functioned as a base in their alliance with the Later Hojo clan.
History and Background
Background of Construction
While there are no clear historical records regarding the exact construction date of Torinji Castle, it is believed to have been built by the Okami clan around the Eiroku era (1558-1570). This period was the height of the Sengoku period (Warring States period), and in Hitachi Province, the Satake clan was expanding its power, while the local clans of the south were engaged in fierce struggles for survival.
The Okami clan was a local clan based around Ushiku Marsh, and they formed their sphere of influence by building several branch castles centered around Ushiku Castle. It is presumed that Torinji Castle was built as part of this network of branch castles, with the purpose of defending Ushiku Castle and strengthening control over the surrounding area.
The Okami Clan’s Era
The Okami clan was a powerful local clan in southern Hitachi Province, with Ushiku Castle as its base. From the mid to late Sengoku period, the Okami clan formed an alliance with the Later Hojo clan and cooperated in the Later Hojo clan’s expansion of power in northern Kanto.
Torinji Castle, like Ushiku Castle, is thought to have been used as a base for both the Okami clan and the Later Hojo clan. Southern Hitachi Province held a crucial position in the Later Hojo clan’s strategy for controlling Kanto, and the Okami clan’s castles played a vital role as frontline bases. During the Tensho era (1573-1592), Toyotomi Hideyoshi’s efforts to unify Japan accelerated. When the Later Hojo clan was destroyed in the Siege of Odawara in 1590, the Okami clan was also affected.
The Kondo Clan’s Era and the Castle’s Abandonment
After the fall of the Later Hojo clan, this region came under the control of Tokugawa Ieyasu. It is believed that Torinji Castle became part of the Kondo clan’s territory, but many details remain unclear.
In the Edo period, Torinji Castle lost its role as a military base and is thought to have been abandoned. In times of peace, mountain castles and hilltop castles were difficult to maintain, and many medieval castles met a similar fate.
Structure
Characteristics of the Castle’s Layout
Torinji Castle is a hilltop castle that skillfully utilizes the topography of the plateau, and has a multi-bailey layout with multiple baileys. The castle grounds are roughly rectangular in shape, measuring approximately 150 meters north-south and 70 meters east-west. The structure consists of the main enclosure (Honmaru) surrounded by the second and third enclosures (Ninokuruwa).
The castle’s defenses were reinforced by deep dry moats and high earthen ramparts. The moat in front of the third enclosure is the largest within the castle grounds. Even today, this moat is over 5 meters deep, and it is estimated to have been even deeper at the time of construction.
Major Remains
Main Enclosure (Honkuruwa)
The main enclosure, located in the center of the castle, is situated at the highest elevation. Surrounded by earthen ramparts, it is believed to have housed the lord’s residence and important facilities. Parts of the earthen ramparts remain well-preserved today.
Second Enclosure (Ninokuruwa)
Adjacent to the main enclosure, the second enclosure served to defend it. A dry moat separated it from the main enclosure, preventing enemy intrusion.
Third Enclosure
The Third Enclosure, which forms the outer part of the castle, is the largest enclosure in terms of area. In front of this enclosure is the largest dry moat within the castle grounds, making it one of the highlights of Torinji Castle.
Dry Moat
The most distinctive feature of Torinji Castle is its deep and large dry moat. The moat in front of the Third Enclosure, in particular, is approximately 10 meters wide and over 5 meters deep, overwhelming visitors. The difference in elevation from the bottom of the moat to the top of the earthen rampart reaches nearly 10 meters in some places, demonstrating the high level of castle construction technology of the Sengoku period.
The dry moat was not merely a ditch, but a military facility designed to slow enemy advances and facilitate attacks with bows, arrows, and firearms. The moat’s shape is a type called a “box moat,” with a flat bottom, designed to trap enemies within it and prevent them from moving.
Earthen Ramparts
Earthen ramparts surround the enclosures, and sections of these ramparts, 2-3 meters high, remain in various places today. It is presumed that fences and walls were erected on top of the earthworks, enhancing the castle’s defensive capabilities.
Umadashi
There are traces of a defensive structure called an umadashi at the castle’s entrance. An umadashi was a small enclosure built in front of the castle gate, serving to prevent direct enemy attacks and facilitate friendly sorties.
Defensive System
The defensive system of Torinji Castle is based on a combination of deep dry moats and high earthworks. The enclosures are separated by trenches, and each enclosure functions as an independent defensive base.
The routes to the castle were limited, forcing the enemy to cross the deep moats. Attacks against enemies attempting to cross the moats could be launched from the top of the earthworks with bows and arrows, stones, and firearms, allowing for effective defense.
Furthermore, the arrangement of the enclosures is in a linear fashion, incorporating the concept of multi-layered defense where even if one enclosure is breached, the next enclosure can provide defense. This structure is characteristic of castles from the late Sengoku period, suggesting that Torinji Castle was built relatively recently. ## Remains
Existing Remains
The remains of Torinji Castle are among the best-preserved medieval castles in Ibaraki Prefecture. The main remains that still exist are as follows:
Dry Moat
The largest dry moat within the castle grounds is located in front of the third enclosure and still maintains a depth of over 5 meters and a width of approximately 10 meters. The slope of the moat is steep, making it difficult to climb. This moat is the main highlight when visiting the castle ruins and is a valuable remains that allows visitors to experience the castle construction techniques of the Sengoku period.
In addition, several traces of trenches separating enclosures and dry moats surrounding the castle can be seen. Although parts of these moats are filled in, their size and arrangement allow us to understand the castle’s defensive system.
Earthworks
Earthworks surround each enclosure, and earthworks 2-3 meters high remain in good condition. Walking along the earthworks allows you to understand the castle’s structure and the surrounding terrain.
The earthworks of the main enclosure are particularly well-preserved, retaining much of their original appearance. Observing the cross-section of the earthworks reveals that they were constructed using a technique called rammed earth (hanchiku), where soil was compacted.
Enclosures
The main enclosure, second enclosure, and third enclosure are still clearly identifiable as flat surfaces. The size and arrangement of the enclosures provide insight into the castle’s scale and structure.
The main enclosure is approximately 30 meters square and is presumed to have housed the lord’s residence and important facilities. The second and third enclosures served as defensive structures protecting the main enclosure.
Traces of a Horse Outwork
Near the castle entrance, traces of a small enclosure believed to be a horse outwork can be seen. A horse outwork is a characteristic defensive structure of castles from the late Sengoku period, indicating that Torinji Castle incorporated relatively recent castle construction techniques. ### Preservation of the Remains
The remains of Torinji Castle are relatively well-preserved because they escaped large-scale development after the castle’s abandonment. The dry moats and earthworks, in particular, remain clearly visible, making them valuable resources for castle research.
Some of the baileys are now used as farmland or forests, and while there are changes to the terrain, the basic structure of the castle remains intact. In recent years, local preservation societies have been carrying out maintenance activities, creating an environment that is more accessible to visitors.
Archaeological Materials
Excavation and Artifacts
While no full-scale excavation has been conducted at Torinji Castle, several artifacts have been identified through surface collection and small-scale surveys.
The unearthed artifacts include fragments of pottery, earthenware, and roof tiles from the Sengoku period. These artifacts support the conclusion that the castle was in use from the late 16th to the early 17th century.
Of particular note are the pottery fragments, such as Tokoname ware and Seto ware. These were luxury goods of the time and serve as valuable historical documents illustrating the lord’s economic power and trading network.
Historical Documents
While historical documents concerning Tōrinji Castle are limited, we can indirectly learn about its history from documents related to the Okami clan and Ushiku Castle.
Geographical records such as the “Kanto Hasshū Kosenroku” and “Hitachi Shiryō” describe the Okami clan’s sphere of influence and their relationship with the Later Hōjō clan, providing important information for understanding the historical background of Tōrinji Castle.
Furthermore, the “Shinpen Hitachi no Kuni Shi,” a geographical record from the Edo period, describes castles around Ushiku and mentions the existence of Tōrinji Castle.
Common Names and Alternative Names
Tōrinji Castle has no specific alternative names other than its official name. Locally, it is sometimes simply called “Castle Ruins” or “Tōrinji Castle.”
The origin of the castle’s name is thought to be derived from the nearby temple, Tōrinji, but many details about this temple and its relationship to the castle remain unclear.
Surrounding Castles and Related Historical Sites
Ushiku Castle
Located approximately 1.4 kilometers northeast of Torinji Castle, Ushiku Castle was the base of the Okami clan. Ushiku Castle was a large flatland castle built on a plateau jutting out into Ushiku Marsh, and it had a close relationship with Torinji Castle.
Ushiku Castle also retains well-preserved remains, and visiting it together with Torinji Castle allows for an understanding of the Okami clan’s castle network.
Kosaka Castle
Located approximately 7.0 kilometers southwest of Torinji Castle, Kosaka Castle is also considered one of the Okami clan’s branch castles. Although small in scale, Kosaka Castle is strategically located and is an important castle indicating the Okami clan’s sphere of influence.
Naruma Castle
Located approximately 6.8 kilometers southeast of Torinji Castle, Naruma Castle is a medieval castle located in Ryugasaki City. This castle also occupies a part of the castle network around Ushiku Marsh and is important for understanding the region’s history.
Kannonji Manor, Kuno Castle, Shōjiki Castle, Tōyama Castle
Besides Tōrinji Castle, many other medieval castles exist within Ushiku City, including Kannonji Manor, Kuno Castle, Shōjiki Castle, and Tōyama Castle. These castles tell the story of the complex power relationships in southern Hitachi Province during the Sengoku period.
Tōrinji Castle Highlights and Visitor Guide
The Largest Moat in the Castle Grounds
When visiting Tōrinji Castle, a must-see is the largest moat in the castle grounds, located before the third enclosure. This moat, over 5 meters deep and approximately 10 meters wide, is an impressive relic that demonstrates the high level of castle construction technology during the Sengoku period.
Looking up from the bottom of the moat, you can appreciate the high level of defense achieved by the combination of the height of the earthworks and the depth of the moat. The steep slopes of the moat make it easy to understand how difficult it would have been for enemy soldiers to climb.
View from the Earthen Embankment
Standing on the earthen embankment of the main enclosure, you can overlook the surrounding terrain. Viewing the Ushiku Marsh area and the surrounding plains helps to understand the strategic importance of the castle’s location.
On a clear day, you can see the distant mountains, allowing you to imagine the castle lord watching over his territory from this spot.
Structure of the Enclosures
By observing the arrangement of the enclosures—the main enclosure, the second enclosure, and the third enclosure—you can learn about the structure of a multi-enclosure castle. The placement of the moats and earthen embankments between each enclosure reveals the concept of multiple layers of defense.
Access and Visiting Precautions
From Ushiku Station on the JR Joban Line, take the community bus and get off at “Mikazukibashi Lifelong Learning Center,” then walk for about 5 minutes. If traveling by car, use the parking lot of a nearby public facility.
While the castle ruins are generally open to visitors, some areas are private property, so please be careful not to enter restricted areas. Furthermore, the moat is deep and slippery, so please be very careful when visiting.
We recommend wearing comfortable shoes and bringing insect repellent during the summer months. It’s best to avoid visiting during or after rain, as the ground becomes slippery.
Historical Value of Torinji Castle
Torinji Castle is an important historical site in Ibaraki Prefecture, boasting particularly well-preserved remains among medieval castles. The castle’s largest moat, earthworks, and baileys provide valuable historical information about castle construction techniques of the Sengoku period.
As a castle indicating the sphere of influence of the Okami clan, and as a base in the Later Hojo clan’s strategy for controlling the Kanto region, Torinji Castle occupies an important position in regional history research. As part of a castle network centered around Ushiku Castle, it is indispensable for understanding the political and military situation in southern Hitachi Province during the Sengoku period.
Further full-scale archaeological excavations may reveal even more historical facts. Local preservation societies are also working on maintenance, and it is hoped that its value as a historical heritage site will become more widely recognized.
Summary
Torinji Castle is a flatland castle built by the Okami clan, located in Shinchi-cho, Ushiku City, Ibaraki Prefecture. Measuring 150 meters north-south and 70 meters east-west, it boasts remarkably well-preserved remains, including the largest moat, earthworks, and baileys within the castle grounds.
Estimated to have been built around the Eiroku era, this castle served as a subsidiary castle of Ushiku Castle, supporting the Okami clan’s power base and functioning as an important base in their alliance with the Later Hojo clan. After the fall of the Later Hojo clan in 1590, it became part of the Kondo clan’s territory and is believed to have been abandoned during the Edo period.
Even today, the deep dry moat and high earthworks remain clearly visible, making it a valuable historical site where one can experience the castle construction techniques of the Sengoku period. Easily accessible from Ushiku Station, it is a worthwhile place to visit for castle enthusiasts and history buffs.
By visiting this castle along with other surrounding fortresses such as Ushiku Castle and Kosaka Castle, you can gain a deeper understanding of the power of the Okami clan in southern Hitachi Province during the Sengoku period and the complex regional situation.
