Complete Guide to Sanuma Castle (Miyagi Prefecture): History, Highlights, and Access Information
What is Sanuma Castle?
Sanuma Castle (Sanuma-jo) is a flatland castle site located in Uchimachi, Sanuma, Hazama-cho, Tome City, Miyagi Prefecture. Also known as “Shishiga-jo,” it was called “Sanuma Fortress” during the Edo period. Built on the right bank of the Hazama River, this castle, surrounded by water on three sides, served as a natural stronghold and an important base in the Tohoku region from the late Heian period to the Edo period.
Currently, the site of the main keep has been developed into Shishiga-jo Park and is designated as a Tome City Historic Site. Remains such as earthworks and moat traces remain, conveying the atmosphere of its former glory.
Basic Information on Sanuma Castle
- Location: Uchimachi, Sanuma, Hazama-cho, Tome City, Miyagi Prefecture
- Other Names: Shikaga Castle, Sanuma Fortress
- Castle Structure: Flatland Castle (Water Castle)
- Construction Period: Bunji Era (1185-1190)
- Builder: Terui Taro Takanao (Legend)
- Main Lords: Terui clan, Kasai clan, Osaki clan, Ishikawa clan, Tsuda clan, Watari clan
- Designated Cultural Property: Tome City Designated Historic Site
- Current Status: Shikaga Castle Park
History of Sanuma Castle
Late Heian Period to Kamakura Period: Construction and the Terui Clan
The history of Sanuma Castle dates back to the Bunji Era (1185-1190) at the end of the Heian period. According to tradition, the castle was built by Terui Taro Takanao, a retainer of Fujiwara no Hidehira of Hiraizumi.
A legend says that a deer was buried alive during the castle’s construction to protect it, and this is the origin of its alternative name, “Shikagajo” (Deer Castle). This legend is deeply rooted in the region and is an important element symbolizing the castle’s history and culture.
Sanuma Castle, located within the sphere of influence of the Hiraizumi Fujiwara clan, continued to function as a regional base even after the fall of the Oshu Fujiwara clan.
Nanboku-cho Period: Kitabatake Akiie’s Entry
During the Nanboku-cho period, Sanuma Castle came under the control of the Kasai clan. Around 1338, Kitabatake Akiie, an important figure on the Southern Court side, is said to have entered the castle. During this period, Sanuma Castle played a crucial role in the turmoil of the Nanboku-cho period.
Muromachi to Sengoku Period: The Struggle Between the Kasai and Osaki Clans
During the Bunmei era (1469-1486), Sanuma Naonobu made it his residence. Subsequently, Sanuma Castle entered a period of fierce competition between the Kasai and Osaki clans, two major powers in the Tohoku region.
For a time, the Osaki clan controlled the castle, and the Ishikawa clan, vassals of the Osaki clan, served as castle lords for four generations, starting with Naomura. Throughout the Sengoku period, Sanuma Castle stood on the front lines of the power struggle between the two clans, consistently demonstrating its strategic importance.
Due to its geographical features as a water castle surrounded by water on three sides, it was known as a “castle that was easy to defend and difficult to attack,” and it withstood numerous battles.
Tensho Era: Toyotomi Hideyoshi’s Pacification of Oshu and the Kasai-Osaki Rebellion
In 1590 (Tensho 18), Toyotomi Hideyoshi carried out the Pacification of Oshu, and the territories of the Kasai and Osaki clans were confiscated. Subsequently, Kimura Yoshikiyo was stationed in the area, but discontent among the former retainers grew.
In 1591 (Tensho 19), former retainers of the Kasai and Osaki clans launched a large-scale uprising. This is known as the “Kasai-Osaki Rebellion.” Sanuma Castle is etched in history as the site of the final battle of this rebellion.
The rebellion was suppressed by Date Masamune. For this achievement, Toyotomi Hideyoshi granted Date Masamune a portion of the former Kasai and Osaki territories, including Sanuma. As a result, Sanuma Castle came under the control of the Date clan.
Edo Period: As Sanuma Fortress
In the Edo period, Sanuma Castle came to be known as “Sanuma Fortress.” As Sanuma became part of the Sendai Domain, senior retainers of the Date clan were stationed there.
First, the Tsuda clan (also known as the Yunome clan) became the lords of the castle, and subsequently, the Watari clan ruled the area for generations. During the Edo period, Sanuma Fortress functioned as an important base in the northern part of the Sendai Domain, becoming the political, economic, and cultural center of the region.
The tombs of the castle lords, the Tsuda and Watari families, still remain in the West Wing, located northwest of the castle, preserving the history of their rule.
Preservation and Utilization of the Castle Ruins After the Meiji Restoration:
After the Meiji Restoration, Sanuma Castle was abandoned and developed into a park. The main keep area became Shikagajo Park, a popular recreational spot for citizens.
Currently, it is protected as a Tome City designated historical site, and the remains such as earthworks and moat traces are well preserved. The Tome City History Museum was built on the west side of the castle ruins, exhibiting the history of Sanuma Castle and local cultural assets.
Structure and Layout of Sanuma Castle
Characteristics as a Water Castle
The most distinctive feature of Sanuma Castle is that it is a water castle built on a slightly elevated area on the right bank of the Hazama River. According to old maps, Sanuma Castle was a fortress with a triple moat utilizing natural ponds. Despite being on flat land, it built a strong defensive system by skillfully using water.
The terrain, surrounded by water on three sides, made enemy advances extremely difficult, functioning as a castle that was “easy to defend and difficult to attack.” This water castle structure holds significant value in castle research as a typical example of a flatland castle in the Tohoku region.
Structure of the Main Enclosure
The main enclosure, now developed as Shikagajo Park, retains well-preserved earthen ramparts. At the eastern end of the main enclosure is a raised platform resembling a watchtower base, where a shrine is now located. From this platform, one can overlook the surrounding area, allowing one to imagine its function as a lookout post in the past.
The remains of a well also exist at the main enclosure site, providing insight into how water sources were secured during sieges. The height and shape of the earthen ramparts give a sense of the scale of the defensive facilities at the time.
Layout of the Enclosures
Sanuma Castle had multiple enclosures (kuruwa) arranged around the main keep (honmaru). The area known as the West Enclosure contains the tombs of the Tsuda and Watari clans, indicating the presence of an important facility in the past.
The castle grounds were relatively large, and a comprehensive defensive system was constructed, encompassing not only the main keep but also the surrounding enclosures. Even today, the original layout can be discerned from the topography and traces of the enclosures.
Highlights of Sanuma Castle
Shikagajo Park (Main Keep Site)
The site of the main keep, the heart of Sanuma Castle, is now maintained as “Shikagajo Park.” Walking paths are provided within the park, allowing visitors to stroll through the castle ruins while enjoying the changing seasons.
In spring, cherry blossoms bloom, making it a popular spot for cherry blossom viewing. Visitors can walk along the earthworks, experiencing the scale of the castle in its heyday. Information boards and monuments explaining the history of Sanuma Castle are installed within the park, making it easy for first-time visitors to understand the castle’s history.
Earthworks and Moat Remains
The most impressive remains of Sanuma Castle are the earthworks surrounding the main enclosure. The high earthworks are remarkably well-preserved, allowing one to truly appreciate their function as defensive structures. Walking along the earthworks provides a good understanding of the surrounding terrain and the castle’s structure.
While much of the moat has been filled in, traces of the moat remain in some areas, allowing one to imagine the castle’s former water-based appearance. The terrain on the east side of the main enclosure, in particular, shows remnants of the former moat.
Turret Base and Shrine
The elevated area at the eastern end of the main enclosure is believed to be the former turret base. Currently, a shrine is located there, serving as a place of worship for the local community. Climbing this elevated area offers panoramic views of the surrounding town and the Hazama River, highlighting the castle’s advantageous location.
The view from the turret base is an important point in understanding its function as a lookout post in the past.
Well Remains
The remains of a well are found within the main enclosure site. Securing a water source during a siege was vital to the castle’s survival, and this well was an essential facility for maintaining the castle’s functions. The well remains are a valuable historical site that evokes the castle’s life at that time.
Sanuma Castle Ruins Monument
A stone monument inscribed with “Sanuma Castle Ruins” stands within the park. This monument is a popular spot for commemorative photos, attracting many castle enthusiasts. Information boards explaining the castle’s history are also installed around the monument.
Tsuda and Watari Clan Cemetery (West Wing)
Located in the West Wing, northwest of the castle, are the cemeteries of the Tsuda and Watari clans, who were lords of the castle during the Edo period. This area, lined with the tombstones of successive lords, is an important historical site that conveys the history of Sanuma Castle during the Edo period.
The cemetery is enveloped in a tranquil atmosphere, allowing visitors to reflect on the reigns of the castle lords.
Tome City Historical Museum
Museum Overview
The Tome City Historical Museum is located on the west side of the Sanuma Castle ruins. Admission to this museum is free, and it exhibits the history of Sanuma Castle and cultural artifacts of the Tome region.
The museum displays old maps of Sanuma Castle, the results of archaeological excavations, and materials related to the castle’s lords. Visiting the museum before or after visiting the castle ruins will allow you to gain a deeper understanding of Sanuma Castle’s history.
Exhibits
The exhibits are structured to allow visitors to follow the history of Sanuma Castle chronologically, learning about its transformation from construction to abandonment. There are also abundant materials related to the Kasai-Osaki Rebellion and materials depicting the castle town during the Edo period.
Local archaeological and folklore materials are also on display, allowing for a comprehensive study of the regional history centered around Sanuma Castle.
Former Watari Residence
Near the museum, the former Watari Residence is also preserved. This building, which preserves the architectural style of a samurai residence from the Edo period, is believed to be part of the residence of the castle lord, the Watari clan, and is a valuable historical site for understanding the life of samurai during that time.
Access Information
Access by Train
- From JR Tohoku Main Line “Nitta Station”: Approximately 15 minutes by taxi
- From Tohoku Shinkansen “Kurikoma-Kogen Station”: Approximately 30 minutes by car
Public transportation access is somewhat inconvenient, so renting a car is recommended.
Access by Car
- From Tohoku Expressway “Tsukidate IC”: Approximately 20 minutes via National Route 398
- From Sanriku Expressway “Tome IC”: Approximately 15 minutes
Free parking is available at the Tome City History Museum, from where you can access the castle ruins on foot.
Parking Information
The Tome City History Museum parking lot is available. Parking is free and can accommodate approximately 30 regular-sized cars. It can be used freely during the museum’s opening hours.
Visiting Hours
Shikagajo Park is open 24 hours a day, but for safety reasons, daytime visits are recommended. The Tome City History Museum is open from 9:00 AM to 4:30 PM (closed Mondays, or the following day if Monday is a public holiday).
Nearby Tourist Attractions
Samurai Residences of Tome Town
Located about 15 minutes by car from Sanuma Castle, Tome Town retains many samurai residences and Western-style buildings from the Meiji era. Known as “Miyagi’s Meiji Village,” visitors can see important cultural properties such as the Educational Materials Museum (former Tome Higher Elementary School) and the Police Museum (former Tome Police Station).
Naganuma Lake
Naganuma Lake, the largest natural lake in Miyagi Prefecture, is located about 10 minutes by car from Sanuma Castle. It is also known as a wintering ground for swans, and many swans can be observed during the winter.
Hiratsunuma Lake
Hiratsunuma Lake is known as a famous spot for cherry blossoms and irises. In spring, approximately 1,000 cherry trees bloom, and in early summer, about 30,000 irises create a beautiful landscape.
Points to Note When Visiting Sanuma Castle
Estimated Visiting Time
If you only want to see the castle ruins, it takes about 30 minutes. Including the Tome City History Museum, it takes about 1 to 1.5 hours. Those who want to carefully observe the remains should allow about 2 hours.
Clothing and Items to Bring
Since you will be walking on the earthen ramparts, we recommend wearing comfortable shoes. In summer, insect repellent, a parasol, or a hat will make your visit more comfortable. In winter, be sure to dress warmly.
Photo Spots
- In front of the stone monument at the Sanuma Castle ruins
- View from the top of the main keep’s earthen rampart
- View of the city from the remains of the turret at the eastern end
- Panoramic view of the park during the spring cherry blossom season
Best Season
The spring cherry blossom season (early to mid-April) is the most beautiful time to visit. The season of fresh greenery (May) and the autumn foliage season (late October to early November) are also recommended. In winter, there is a possibility of snow, so please check the weather beforehand.
Cultural Value of Sanuma Castle
Importance in the Study of Flatland Castles in the Tohoku Region
Sanuma Castle occupies an important position in castle research as a typical example of a flatland castle (water castle) in the Tohoku region. Its structure with triple moats is a good example of the development of defensive systems on flat land.
Historical Site of the Kasai-Osaki Rebellion
As the site of the final battle of the Kasai-Osaki Rebellion in 1591, Sanuma Castle is an important historical site symbolizing the transition from the Sengoku period to the early modern period in the Tohoku region, marked by Toyotomi Hideyoshi’s pacification of Oshu and the expansion of Date Masamune’s power.
Regional Historical Identity
The legend of its construction, symbolized by its alternative name “Shikagajo” (Deer Castle), is at the core of the region’s historical identity. Its history of deep involvement with powerful forces in Tohoku, from the Hiraizumi Fujiwara clan to the Date clan, is passed down as a source of regional pride.
Summary
Sanuma Castle (Shikagajo) is a castle that functioned as an important base in the Tohoku region from the late Heian period to the Edo period. This castle ruin boasts a multifaceted history, characterized by its water-surrounded design, fierce battles between the Kasai and Osaki clans, its role as the site of the final battle of the Kasai-Osaki Rebellion, and its function as a strategic stronghold under the Date clan.
Currently, it is maintained as Shikagajo Park, with well-preserved remains such as earthworks and moat traces. The Tome City History Museum offers detailed information about the castle’s history and is free to visit.
When traveling through the Tohoku region, be sure to stop by the Sanuma Castle ruins and experience the rich history etched into this land. The scenery is especially beautiful during cherry blossom season.
