Complete Guide to Iwadeyama Castle (Miyagi Prefecture): A Thorough Explanation from Date Masamune’s Residence to Shiroyama Park
Iwadeyama Castle, located in Osaki City, Miyagi Prefecture, is a historically significant castle that served as the residence of Date Masamune, known as the “One-Eyed Dragon,” before he built Sendai Castle. Currently, it is maintained as Shiroyama Park, with remnants such as dry moats and gate remains conveying the atmosphere of the time. This article comprehensively explains everything you need to know before visiting Iwadeyama Castle, from its history and highlights to access methods.
History of Iwadeyama Castle
Construction and the Era of the Ujiie Clan
The origins of Iwadeyama Castle date back to the Muromachi period. It is said to have been built during the Oei era (1394-1428) by Ujiie Danjo (Ujiie Naomasu), a vassal of the Osaki clan, a branch of the Ashikaga clan who were the Oshu Tandai (governor of Oshu Province). At the time, it was called Iwatezawa Castle and functioned as the residence of a senior retainer of the Osaki clan.
The castle was built on Shiroyama, a hill extending southeastward at an elevation of approximately 108 meters, surrounded by the Egai River and Hiruzawa River. This location was a strategic transportation hub where the Kita-Uzen and Ugo Roads intersected, making it a military and economically important base.
Date Masamune’s Entry and the Renaming to Iwadeyama
In 1591, as a result of Toyotomi Hideyoshi’s pacification of Oshu, Date Masamune was transferred from Yonezawa Castle to Iwatezawa Castle. At this time, Masamune changed the castle’s name from Iwatezawa to Iwadeyama. This renaming is thought to have symbolized the beginning of a new era.
Masamune moved his retainers and townspeople from his former territory of Yonezawa and developed Iwadeyama as his new base. Through the expansion of the castle grounds and the construction of the castle town, Iwadeyama developed into the political and economic center of the Date clan.
Masamune’s 12 Years and the Move to Sendai Castle
Masamune resided at Iwadeyama Castle for approximately 12 years until he moved his residence to Sendai Castle (Aoba Castle) in 1601. This period was crucial for Masamune and a preparatory period for laying the foundation of the Sendai Domain.
Even after the move to Sendai Castle, Iwadeyama Castle remained an important base for the Date clan as the Iwadeyama Fortress. Its continued existence as a fortress was permitted even after the “One Castle Per Province” decree, and members of the Date clan and their senior retainers served as castle lords. Throughout the Edo period, Iwadeyama continued to function as a key point for the northern defense of the Sendai Domain.
Structure and Characteristics of Iwadeyama Castle
Layout and Arrangement
Iwadeyama Castle is a typical mountain castle, with a structure that skillfully utilizes the hilly terrain on the south bank of the Egai River. The castle was broadly laid out as follows:
- Honmaru: Located at the highest point of the northern mountain range, it was the core of the castle.
- Ninokuruwa: A long, narrow enclosure adjacent to the Honmaru.
- Isho: Located on the south side of the hill, near the current Iwadeyama Elementary School and Iwadeyama High School.
- Jokamachi: Established at the foot of the hill.
The castle is characterized by its defensive structure that utilizes the Egai River and waterways as natural moats, making maximum use of the terrain.
Remaining Structures
Currently, the Iwadeyama Castle site is maintained as Shiroyama Park, but many remains that convey the atmosphere of the time remain:
Dry Moats
The dry moats, which played an important role as defensive structures of the castle, can still be clearly seen today. The dry moats around the Honmaru are particularly large in scale, demonstrating the high level of castle construction technology at the time.
Gate Remains
Traces of gates remain throughout the castle, providing clues to the castle’s entrances and movement patterns.
Kuruwa (Enclosure) Remains
The layout of enclosures such as the main keep and second enclosure can be deciphered from the topography, allowing for an understanding of the castle’s overall structure.
Parts of Stone Walls
In some places, parts of the stone walls remain, allowing for an examination of the stonework techniques of the time.
Highlights of Iwadeyama Castle
Development as Shiroyama Park
The Iwadeyama Castle ruins are now open to citizens and tourists as Shiroyama Park. Walking paths are maintained within the park, allowing visitors to stroll through the castle ruins while enjoying the changing seasons. In particular, cherry blossoms bloom profusely in spring, making it a popular spot for cherry blossom viewing.
From the park, you can enjoy a panoramic view of the town of Iwadeyama and the surrounding mountains, allowing you to appreciate why Masamune chose this location as his castle.
Former Yubikan and Garden
At the foot of Iwadeyama Castle lies the Former Yubikan, the domain school of the Date clan, and its garden. The Yubikan was a school established during the Kanbun era (1661-1673) for the education of the children of Date family retainers, and is now designated as a national historic site and place of scenic beauty.
Yubikan Building
The main building is a hip-and-gable roofed structure with a thatched roof, exuding a simple yet dignified appearance. Although damaged in the Great East Japan Earthquake, it has reopened to the public after restoration work.
Pond-Centered Stroll Garden
The garden attached to the Yubikan is a stroll garden centered around a pond, a beautiful space that embodies the finest Edo period landscape gardening techniques. Visitors can enjoy the scenery throughout the seasons, and it is especially crowded with tourists during the autumn foliage season.
The garden features a tea house, stone bridge, and lanterns, offering a glimpse into the refined aspects of samurai culture. When visiting Iwadeyama Castle, we highly recommend also visiting the Yubikan.
Historical Sites Associated with Masamune
The area around Iwadeyama is dotted with historical sites associated with Date Masamune. Within Shiroyama Park, there are explanatory signs and monuments related to Masamune, allowing visitors to trace his footsteps.
Access Information
Access by Train
Nearest Station: JR Rikuu East Line “Yubikan Station”
The entrance to Shiroyama Park is approximately a 15-minute walk from the station. Yubikan Station is an unmanned station, but you can enjoy the quiet atmosphere of Iwadeyama while walking.
Access from Sendai Station:
Approximately 15 minutes by JR Tohoku Shinkansen to Furukawa Station, then transfer to the JR Rikuu East Line and approximately 20 minutes to Yubikan Station.
Access by Car
Tohoku Expressway:
- Approximately 20 minutes from Furukawa IC via National Route 47
- Approximately 15 minutes from Chojahara SA Smart IC
Parking:
Free parking is available around Shiroyama Park and the former Yubikan. However, it may become full during peak seasons such as cherry blossom season, so early arrival is recommended.
Address and Map
Location: Iwadeyama, Osaki City, Miyagi Prefecture
Shiroyama Park is located north of the Iwadeyama town center, and the former Yubikan is at the foot of Shiroyama Mountain. You can easily find the location by searching for “Shiroyama Park” or “Former Yubikan” on your car navigation system or smartphone map app.
Tourist Information
Visiting Hours and Fees
Shiroyama Park:
- Free admission
- Daytime strolling is recommended
Former Yubikan:
- Opening Hours: 9:00 AM – 4:30 PM (Last entry 4:00 PM)
- Closed: Mondays (or the following day if Monday is a public holiday), New Year holidays
- Admission Fee: General 350 yen, High school students 260 yen, Elementary and junior high school students 170 yen
- *Fees may change, so it is recommended to check before visiting.
Estimated Visiting Time
- Shiroyama Park only: Approximately 30 minutes to 1 hour
- Including Former Yubikan: Approximately 1 hour 30 minutes to 2 hours
- For a leisurely stroll: 2 to 3 hours
Recommended Time to Visit
Spring (Early to Mid-April):
Known as a famous cherry blossom viewing spot, Shiroyama Park is bustling with cherry blossom viewers. The contrast between the cherry blossoms and the castle ruins is beautiful, making this the most popular season.
Autumn (late October to early November): The autumn foliage is stunning, especially at the Yubikan Garden. Enjoy a historical stroll in a tranquil atmosphere.
Summer (July to August): Enjoy the lush green scenery, but be sure to take precautions against the heat and insects.
Winter (December to February): The castle ruins covered in snow have a charming atmosphere, but be careful as the ground can be slippery.
Nearby Tourist Attractions
Iwadeyama Castle Town
The town of Iwadeyama retains the atmosphere of a former castle town. Old merchant houses and storehouses are scattered throughout, allowing you to stroll through a historic streetscape. There are also many shops selling local specialties, making it ideal for souvenir shopping.
Naruko Onsenkyo
Located about 30 minutes west of Iwadeyama by car, Naruko Onsenkyo is one of Tohoku’s leading hot spring resorts. A plan to relax and unwind in the hot springs after a historical walk is highly recommended.
Sensory Museum
This interactive museum, located in the town of Iwadeyama, features exhibits that engage all five senses. It’s a popular spot for families.
Historical Significance of Iwadeyama Castle
The Base for Date Masamune’s Rise
Iwadeyama Castle was the base for Date Masamune’s transitional period, as he rose from being the ruler of Tohoku to becoming a daimyo of the Sendai Domain with a 620,000 koku (unit of rice production) territory. For Masamune, who was transferred from Yonezawa due to Toyotomi Hideyoshi’s pacification of Oshu, Iwadeyama became the starting point for his new domain management.
Here, Masamune reorganized his retainers, built a castle town, and promoted industry, laying the foundation for the later Sendai Domain. Furthermore, it is believed that many of Masamune’s ambitious projects, such as the dispatch of the Keichō Embassy to Europe, were conceived during his time at Iwadeyama.
Northern Defense Base of the Sendai Domain
Even after the relocation to Sendai Castle, Iwadeyama Castle (Iwadeyama Fortress) continued to function as an important base for the northern defense of the Sendai Domain. Throughout the Edo period, members of the Date clan and their senior retainers served as castle lords, contributing to the stability of the territory.
Center of Education and Culture
With the establishment of the domain school, Yūbikan, Iwadeyama also developed as a center of education. The Date clan’s policy of emphasizing academics as well as martial arts fostered a cultural environment in this area.
Points to Note When Visiting Iwadeyama Castle
Clothing and Equipment
Shiroyama Park is the site of a mountain castle and has an undulating terrain. It is recommended to wear comfortable shoes and clothing suitable for walking. In summer, insect repellent is recommended, and in winter, warm clothing is essential.
Check the Weather
The ground can become slippery in rainy weather. Please check the weather forecast and consider preparing rain gear.
Photography
Photography is permitted in Shiroyama Park, but there may be restrictions on photography inside the former Yubikan building. Please follow the instructions of the staff.
Local Manners
Shiroyama Park is adjacent to a residential area. Please be considerate of local residents and avoid causing any disturbance with noise.
Summary
Iwadeyama Castle is an important historical site indispensable to understanding the history of Date Masamune. Currently, it is maintained as Shiroyama Park, and the remains such as the dry moat and gate ruins convey the atmosphere of the time. By visiting the former Yubikan building and garden at the foot of the mountain as well, you can experience the multifaceted charm of samurai culture.
Its convenient location, about an hour’s drive from Sendai city, is also a major attraction, making it ideal as part of a Sendai sightseeing trip or as a stopover on the way to Naruko Onsen. Please visit Iwadeyama Castle and enjoy its beauty throughout the seasons, from cherry blossoms in spring to autumn leaves.
Standing on this land where Masamune spent 12 years, and imagining the scenery the one-eyed dragon saw, while reflecting on history, will surely be an unforgettable experience. Iwadeyama Castle is a fascinating spot that I would recommend not only to history buffs, but to everyone who loves nature and culture.
