Iwamura Castle is renowned as one of Japan’s Three Great Mountain Castles, alongside Takatori Castle in Nara Prefecture and Bitchu Matsuyama Castle in Okayama Prefecture. Originally built in the early Kamakura period, the castle is particularly famous for its association with Otsuya no Kata, an aunt of the powerful warlord Oda Nobunaga, who ruled the castle during the late Sengoku period.
Built at an elevation of 717 meters, the fortress cleverly utilized a natural difference in elevation of approximately 180 meters to strengthen its defenses. It is also known as Kirigajo, or “Castle of the Mist,” and its appearance rising above a sea of clouds evokes the image of a castle floating in the sky. Although the castle buildings no longer survive, its impressive stone walls remain. Iwamura Castle has also been selected as one of Japan’s 100 Famous Castles.
At the foot of the castle, a historic castle-ruins park features a reconstructed Taiko Turret, Utako Shimoda’s Study House, the main gate of the former Chishinkan school, and a Japanese iris garden. The Iwamura Historical Museum displays materials relating to the castle’s history and local culture.
Ena City, in southeastern Gifu Prefecture, is a region rich in natural beauty and historical heritage. About 20 minutes by car from the city center, Iwamura is a historic town known for stories about a remarkable female castle lord who lived during the Sengoku period.
Iwamura Castle has a history spanning more than 800 years. According to local tradition, Otsuya no Kata governed the castle with compassion and worked to protect the people under her rule until the very end. Because of this enduring story, Iwamura is affectionately known as the “Town of the Female Castle Lord.”
Iwamura Castle was built in the early Kamakura period by Toyama Kagetomo, a retainer of the Kamakura shogunate. His descendants, known as the Iwamura Toyama clan, subsequently served as the castle’s lords.
During the Sengoku period, Otsuya no Kata, an aunt of Oda Nobunaga, ruled the castle. Iwamura became the focus of a struggle between the Oda and Takeda clans. The castle was eventually recaptured by Oda Nobunaga’s forces, with Nobunaga’s eldest son, Oda Nobutada, serving as the commander of the siege.
During the Edo period, the castle was governed by successive families, including the Matsudaira and Niwa clans. The surrounding castle town was also developed during this era.
The castle suffered damage in the Hoei Earthquake of 1707, but the area continued to serve as an important regional center. The establishment of a domain school further contributed to local education and culture.
Following the Castle Abolition Order of 1873, the castle buildings were dismantled, although the stone walls were left standing.
The Iwamura Historical Museum opened in 1972 to preserve and present the area’s heritage. In 2006, Iwamura Castle was designated one of Japan’s 100 Famous Castles, recognizing its historical and architectural significance.
The park at the former castle site features wooden reconstructions of the Omote-mon Main Gate and Taiko Turret. Together with the surviving stone walls and moat remains, these structures offer a glimpse of the castle as it once stood.
The elevated setting and rugged terrain also reveal how the castle’s builders took advantage of the natural landscape to create a formidable mountain fortress.
Located at the foot of the castle on the former site of the Iwamura domain lord’s residence, the Iwamura Historical Museum preserves and exhibits materials related to Iwamura Castle, the Iwamura domain, and the development of the surrounding castle town.
Next to the museum is the Iwamura Folk Museum, which displays materials documenting traditional local life and customs. Its building is a traditional farmhouse relocated from Kinomi in the former Kamiyahagi Town, Ena District.
The historic town below the castle retains the atmosphere of an Edo-period settlement. Traditional streets and buildings create a charming setting for a leisurely walk, allowing visitors to experience the history and character of this former castle town.
Combined with the castle ruins and historical museums, the town offers an opportunity to explore the legacy of Iwamura’s samurai heritage and the story of its famous female castle lord.