Guide
Marunuma Dam, located in Katashina Village, Gunma Prefecture, is a remarkable example of a buttress-type dam. Completed in the early Showa era, this dam was the first power-generating dam in Japan to be designated as a National Important Cultural Property due to its historical and architectural significance. The buttress structure is a rare engineering style, and Marunuma Dam stands as one of the largest existing dams of this type. The dam's body is supported by unique vertical beams, creating a striking silhouette that serves as a living testament to the history of modern civil engineering.
Marunuma Dam was completed in 1931. The design and construction techniques used by the Jomo Electric Power Company at the time were highly advanced and progressive. It has also been selected as a "Selected Civil Engineering Heritage" by the Japan Society of the Civil Engineers. Even after more than 70 years, it continues to operate while maintaining its original form. The designation as an Important Cultural Property is due to the preservation of the design philosophy and construction technology of that era, serving as a symbol of the civil engineering that supported Japan's modernization.
The dam's body features a unique design of massive concrete beams and columns arranged in a grid-like pattern. There are specific spots where you can view this buttress structure from the front. Additionally, the Marunuma Lake spreads around the dam, creating a landscape where the massive artificial structure and the surrounding natural environment become one. Collecting the