Sakado Bridge is a historic road bridge spanning the Tenryu River in Nakagawa Village, Kamiina District, Nagano Prefecture. Designated as a National Important Cultural Property, the elegant bridge is one of the village’s most significant cultural landmarks.
The bridge forms an important part of the local road network, connecting with National Route 153 and Prefectural Route 18, the Ina-Ikuta-Iida Line, via Prefectural Route 217. At the same time, it preserves an important chapter of the region’s transportation history and remains a striking part of the landscape along the Tenryu River.
Completed in 1933, Sakado Bridge is a reinforced-concrete single-arch bridge known as an open-spandrel deck arch bridge. It measures 77.8 meters in total length, with a bridge height of 20 meters, roadway width of 5.5 meters, arch span of 70 meters, and an arch rise of 12 meters.
When it was built, its 70-meter span was the largest of its kind in Japan, making the bridge an important engineering achievement of its era. Even today, among bridges of this type constructed before 1965, it remains the longest in Japan.
The graceful concrete arch contrasts beautifully with the rugged mountains and flowing waters of the Tenryu River, giving Sakado Bridge both engineering significance and considerable scenic appeal.
The history of Sakado Bridge began long before the present structure was built. The site was originally a ferry crossing used to travel across the Tenryu River.
In 1887, a wooden bridge was constructed for the first time. Two years later, in 1889, the bridge was completed under the name “Sakado Bridge.” However, the Tenryu River was notorious for severe flooding and was often called the “Wild Tenryu.” The wooden bridge was washed away twice.
In 1903, it was replaced by a suspension bridge as a measure against flooding. At that time, the bridge was operated as a toll bridge, and users were charged a fee until 1920.
The residents of the surrounding communities understood how essential the bridge was to everyday life. In 1919, local people raised donations so that the village could purchase the bridge and donate it to Kamiina District.
In 1923, the bridge became part of the Nagano prefectural road network and came under prefectural management. However, the suspension bridge was difficult to maintain and raised concerns about safety. As a result, local demand grew for a more durable reinforced-concrete bridge.
Construction of a new bridge began in 1932 as a Nagano Prefecture public works project. Financial assistance was provided by Yahagi Hydroelectric, and the new bridge was completed the following year.
When it opened, newspapers praised it as “Sakado Bridge, the finest in the Orient,” and the structure quickly became a source of pride for the local community.
During the Pacific War, the bridge’s original stone or concrete entrance pillars and street lamps were removed under government orders for the collection of metal for the war effort.
For many years, these features remained absent. Then, in 1991, local residents raised funds to restore the bridge’s entrance pillars and street lamps based on their original designs, bringing back elements of its historic appearance after approximately 50 years.
Repair work was also carried out, and the restoration was completed in 1994. Sakado Bridge once again presented much of the elegant appearance it had possessed when it was first constructed.
After Sakado Bridge was completed, local residents worked to improve the area around the bridge and planted cherry trees and azaleas.
In spring, the cherry trees bloom on both sides of the bridge, creating a spectacular tunnel of blossoms. The combination of the graceful arch, flowering trees, river, and surrounding mountains makes this one of Nakagawa Village’s most memorable spring landscapes.
The area around Sakado Bridge became known as Sakado Gorge, or Sakado-kyo, and is now recognized as one of the village’s scenic destinations. The name has even been incorporated into the nearby intersection on National Route 153, which is known as the “Sakado Gorge” traffic signal.
In 2010, Sakado Bridge was registered as a National Registered Tangible Cultural Property. At the time, among more than 3,800 road bridges managed by Nagano Prefecture, it was the only one to hold this designation.
Its cultural and historical importance was recognized at an even higher level on December 23, 2020, when Sakado Bridge was officially designated a National Important Cultural Property.
Its earlier registration as a Registered Tangible Cultural Property was subsequently removed as a result of the higher designation. Today, the bridge is valued not only as transportation infrastructure but also as an important example of modern Japanese civil engineering and regional history.
In 2011, Sakado Park was developed upstream on the right bank of the river near the bridge. The park has become particularly popular during the cherry blossom season.
From the park, visitors can enjoy views of Sakado Bridge framed by flowering cherry trees. The scenery is especially popular with photographers seeking to capture the relationship between the historic bridge and the surrounding spring landscape.
Near Sakado Bridge is the former site of the headquarters where Yomeishu was once produced. Historic storehouses have been renovated as a small museum space, and a commemorative monument remains on the site.
The area offers another opportunity to discover the industrial and commercial history of the region while exploring the surroundings of the bridge.
On the left bank once stood Sakado Ryokan, a traditional inn that was popular with anglers and visitors to the area. Although the inn is no longer in business, its former presence forms part of the local history surrounding the bridge and river.
Sakado Bridge is far more than a crossing over the Tenryu River. Its history reflects the development of transportation in the region, the efforts of local residents, advances in bridge engineering, and the changing needs of communities from the Meiji era through the modern age.
The elegant 1933 concrete arch stands in striking harmony with the Tenryu River and the mountains of the Ina Valley. In spring, cherry blossoms transform the bridge into a spectacular scenic destination, while fresh greenery in summer and colorful foliage in autumn provide completely different views.
For travelers exploring the Ina Valley, Sakado Bridge offers a fascinating combination of modern Japanese engineering heritage, local history, and seasonal natural beauty. A walk around Sakado Park and the surrounding river landscape is an especially rewarding way to appreciate this remarkable bridge and the story it continues to tell.