Lake Tojo is an artificial lake in Kato City, Hyogo Prefecture, formed by the construction of Kamogawa Dam. Surrounded by wooded hills and scenic rock formations, it is a peaceful destination for visitors who enjoy nature, fishing, boating, and outdoor recreation.
Construction of Kamogawa Dam began in 1949 and was completed in November 1951, creating the lake now known as Lake Tojo. Viewed from above, the lake has a distinctive shape resembling a giant dragon, a feature that has contributed to its appeal as a scenic destination. The name Unryuko, meaning “Dragon Cloud Lake,” was initially considered, but the name Lake Tojo was ultimately chosen to reflect the local area.
The lake was developed primarily to secure a reliable supply of irrigation water for the agricultural land of the Harima Plain. Today, it serves both this practical purpose and as a popular destination for leisure activities. Visitors can enjoy black bass fishing, smelt fishing, and boating, while the surrounding landscape offers opportunities to appreciate the area’s natural beauty. The lakeside area also includes Kiyomizu-dera Temple and residential developments that began in 1966.
Lake Tojo is known for the Eight Scenic Views of Lake Tojo, a collection of distinctive rock formations, valleys, and waterside landscapes that showcase the area’s geological character and local history.
Shaped by weathering and erosion over time, Fudo-iwa has a mysterious appearance that makes it one of the area’s memorable rock formations.
These rocks are named for their shapes, which are said to resemble two sisters, giving the formation a distinctive and evocative character.
Scattered rocks throughout the valley create an attractive natural landscape, offering a glimpse of the rugged scenery surrounding the lake.
Kurama Gorge is characterized by rocky terrain and steep valley scenery, making it a striking feature of the area’s natural landscape.
This rocky cave takes its name from the impression that it could serve as a nesting place for eagles. Its rugged appearance adds to the area’s dramatic scenery.
Horai Gorge is a scenic valley associated with local legends and traditional stories, lending an air of mystery to its natural surroundings.
Weathered into a formation resembling a traditional folding screen, Byobu-iwa is notable for its unusual shape and natural texture.
Suiten-gu is a particularly distinctive sight, appearing to emerge from the lake. The shrine is associated with the memory of the former Doi settlement, which was submerged when the dam was built. A guardian deity is enshrined here, reflecting the area’s history and the community’s connection to the land that once lay beneath the water.
Kamogawa Dam stands on the Kamogawa River in Kurotani, Kato City, within the Kako River system. Managed directly by the Ministry of Agriculture, Forestry and Fisheries through its Kinki Regional Agricultural Administration Office, the dam is a gravity-type concrete structure standing 43.5 meters high.
The dam was built as the central facility of the Tojogawa National Irrigation Project, which was designed to provide a dependable water supply to farmland in the central Harima Plain. It was also the first concrete dam constructed by Japan’s former Ministry of Agriculture and Forestry. Its reservoir became Lake Tojo, transforming the surrounding landscape into a destination known for both agricultural importance and tourism.
Rice cultivation has been practiced in the Harima Plain since the middle of the Yayoi period, more than two thousand years ago. However, the region’s Seto Inland Sea climate brings relatively little rainfall, and water shortages have long been a challenge for agriculture. As a result, the area developed a dense network of irrigation ponds, comparable to other major pond-rich agricultural regions of Japan.
During the Meiji period, water-resource development along the Kako River system progressed, including the construction of the Oboke River waterway, which brought water from a tributary. Nevertheless, these measures did not fully resolve the region’s chronic water shortages. In 1924, local leaders representing five districts and 27 municipalities formed an alliance to promote agricultural development in eastern Harima and petitioned the national government for a large-scale irrigation project. The plans were interrupted as Japan’s wartime mobilization intensified.
After World War II, Japan faced a severe food shortage, making the expansion of farmland and increased agricultural production urgent national priorities. In 1947, the Ministry of Agriculture and Forestry launched a national irrigation program covering four river systems. The plan for Kamogawa Dam was developed as part of this broader effort.
Building the dam required the former settlement of Doi to be submerged beneath the reservoir. The small community consisted of seven households and 51 residents, who cultivated approximately seven hectares of farmland. Following negotiations over compensation, the residents had to leave their homes and ancestral land.
After the compensation arrangements were settled, construction took four years, and the dam was completed in November 1951. It continues to play an important role in supplying irrigation water to farmland across the Harima Plain. The history of Doi is also remembered through Suiten-gu, one of the Eight Scenic Views of Lake Tojo.
Following the completion of Kamogawa Dam, the Tojogawa National Irrigation Project continued to expand. By 1964, the associated water-intake facilities and irrigation channels had been completed, bringing irrigation benefits to approximately 4,000 hectares of farmland.
Because water shortages remained a concern across the wider Harima Plain, further projects were undertaken throughout the Kako River system. Beginning in 1970, the East Harima Irrigation Project developed additional dams, including Kawashiro Dam on the Sasayama River, Okawase Dam on the Tojo River, and Dontobiki Dam on the Shisen River, a tributary of the Mino River. These facilities significantly improved the region’s agricultural water supply.
Lake Tojo and its surrounding area, together with Kiyomizu-dera Temple, became part of Kiyomizu-Tojo Lake Prefectural Natural Park in 1957. The lake developed into one of the principal sightseeing destinations in the Harima region, attracting visitors with its unusual outline, scenic rock formations, boating opportunities, and fishing spots.
In 1969, Tojo Lake Land amusement park opened, becoming a popular leisure destination and the only amusement park in the Harima region at the time. During the 1990s, it attracted an average of around 800,000 visitors annually. However, changing leisure preferences and economic conditions led to its closure in 2000.
The area subsequently welcomed Tojoko Toy Kingdom, a family-oriented theme park that continues to draw visitors. Alongside fishing and outdoor recreation, the park helps maintain Lake Tojo’s appeal as a destination for families and nature lovers.
Aqua Tojo is a recreational facility where visitors can enjoy activities connected with water. It provides another option for spending time outdoors in the Lake Tojo area.
Popular with families, Tojoko Toy Kingdom is a theme park where children can enjoy a variety of toy-themed attractions and play experiences. It is one of the area’s best-known leisure destinations.
Located near the lake, Hotel Green Plaza Tojoko offers accommodation for visitors wishing to relax and explore the surrounding attractions over a longer stay.
Located in the surrounding hills, Kiyomizu-dera is a historic Buddhist temple and the 25th temple on the Saigoku Kannon Pilgrimage. It can be combined with a visit to Lake Tojo for a day of sightseeing that brings together natural scenery and religious heritage.
Lake Tojo and Kamogawa Dam are approximately a 10-minute drive from the Hyogo-Tojo Interchange on the Chugoku Expressway. The area is also close to Okawase Dam, making it possible to visit more than one dam during the same trip.
Whether you are interested in the history of Japanese irrigation, the distinctive rock formations of the Eight Scenic Views, fishing and boating, or a family outing to Tojoko Toy Kingdom, Lake Tojo offers a varied experience in the natural landscape of Hyogo Prefecture.