Guide
Chatsubomi-goke Park, located in the mountains of Nakanojo Town, Gunma Prefecture, is the largest breeding ground in Japan for the Chatsubomi-goke moss. This area provides the perfect highly acidic environment required for this rare moss to thrive. In 2017, the site was officially designated as a National Natural Monument, specifically recognized as the "Iron-forming Site of the Rogo Chatsubomi-goke Biological Community." The park is a fascinating destination where the remnants of industrial history and natural wonder merge seamlessly.
The site is the former location of the "Gunma Iron Mine." Development began around 1943 to secure metal resources, with large-scale mining operations conducted to address resource shortages during the war era. Historically, the site utilized railways and ropeways (aerial tramways) to transport iron ore. Although mining ceased in 1965 due to the depletion of resources, the site has been preserved and developed into a park that showcases its unique topography. From a geological perspective, the landscape is a striking result of volcanic activity, creating an acidic environment rich in iron ions that has shaped the local ecosystem.
Visitors can observe the Chatsubomi-goke moss in its natural habitat, adapted to highly acidic conditions. This moss grows alongside the formation of limonite (iron ore) caused by biological activity in an iron-rich environment. The sight of the vivid green moss blanket covering the surrounding rocks and terrain is a spectacle unique to this location. Additionally, the rugged terrain left behind by the former mining operations serves as a powerful testament to the area's industrial history.
To see the most vibrant colors of the Chatsubomi-goke moss, it is highly recommended to visit between June and August, when the plant activity is most intense. During the summer months, the landscape feels particularly alive with biological energy. The park is open from 08:45 to 15:00, and we recommend visiting during the bright daylight hours to fully appreciate the colors.
The primary activity is nature observation. You can walk through the trails to observe the rare Chatsubomi-goke moss in its natural habitat. It is a peaceful environment where you can experience the intersection of natural geological formations and industrial ruins. No specialized botanical knowledge is required to enjoy the visual splendor of this unique landscape.
The Nakanojo area is dotted with various hot spring (onsen) resorts and other natural scenic spots. The region is characterized by the flow of the Agatsuma River and landscapes shaped by volcanic activity, making it an excellent destination for travelers interested in exploring diverse geological and natural features.
As this is a protected natural park, please show respect for the plants and the environment. Because the terrain can be uneven and unstable in certain areas, sturdy walking shoes or hiking shoes are highly recommended. Please ensure you complete your visit within the park's operating hours. We ask all visitors to follow local rules to help preserve this precious natural environment.