The park's moss requires highly acidic water (pH 3.0 to 4.0) to grow, an environment created by the region's volcanic activity.
The name 'Chatsubomi' refers to the tea-bowl shaped depressions formed by iron deposits in the area.
It is one of the few places in Japan where this specific moss species thrives in such a large, continuous carpet.
The site was once used for open-pit mining of limonite before its conversion into a protected conservation area.
The acidic water prevents the growth of most competing plant species, allowing the moss to dominate the landscape.
Chatsubomi Moss Park features one of the largest colonies of alpine moss (chagoke) in Honshu, thriving in the highly acidic, iron-rich water of the former Anabudaira iron mine. The park covers an area characterized by its naturally occurring peat moss beds, which require a specific acidic environment to survive. Visitors traverse the moss fields via a network of wooden boardwalks and viewing platforms designed to protect the fragile ecosystem. The area was formerly the site of a limonite mine, resulting in unique topographical features and mineral-rich springs. It is designated as a National Natural Monument due to its rare ecological significance. The moss changes appearance throughout the seasons, shifting in density and texture based on water flow and light conditions.
The main viewing platform overlooking the largest, most dense expanse of the moss colony.
Bring insect repellent, as the damp, forest-like environment attracts mosquitoes and other forest insects.
Use the wooden boardwalks strictly, as the moss is extremely sensitive to foot traffic and human weight.
Prepare for rapid weather changes, as the park is located at a high elevation in the Gunma mountains.
Do not attempt to collect moss or water samples; the site is a protected natural monument and such activities are restricted.
Closed during winter months due to heavy snowfall; typically opens in late spring and closes in late autumn.
Stay exclusively on the provided boardwalks; touching or stepping on the moss is strictly prohibited to prevent damage to the delicate ecosystem.
