
Guide
Yashima Wetlands (Yashimagahara Wetlands) is a premier high-altitude wetland located in the northwestern part of the Kirigamine Plateau at an altitude of 1,630m in the Chushin region of Nagano Prefecture. Spanning a total area of 43.2 hectares, its history is estimated to be 12,000 years old. Designated as a National Natural Monument in 1939, the site holds immense academic and cultural value. Within the vast grasslands, a diverse range of flora, centered around Sphagnum moss, thrives in harmony with the surrounding mountains and the deep blue sky, offering visitors a deeply moving experience of nature.
This wetland has been shaped by the natural processes of the ancient world. The peat layer reaches a thickness of 8.05m, with organic matter accumulating over countless years to support a rich and stable ecosystem. Historically, the area has maintained an incredibly diverse flora, including approximately 18 different species of Sphagnum moss. The surrounding region has a long history of living alongside nature, and today, the wetlands are cherished and protected by hikers and nature enthusiasts as an iconic natural landscape of the Kirigamine Plateau.

The greatest charm of Yashima Wetlands lies in its vibrant botanical displays that change with the seasons. In June, the landscape is blanketed in the bright colors of Rengetutsuji (Japanese Azalea), and in July, the Nikko Kisuge (Daylily) blooms in abundance, turning the entire wetland into a colorful spectacle. Visitors can also experience the sounds of life, such as the calls of the Schlegel's Green Tree Frog, which was selected as one of the "100 Soundscapes of Japan" by the Ministry of the Environment. The walking course that circles the wetland (approx. 3.8km) is well-maintained with minimal elevation changes, offering a spectacular panoramic view of the surrounding mountains.
The character of the wetlands changes dramatically depending on the season:

Various activities allow you to connect closely with nature around the wetlands. The well-maintained circular trail (approx. 1 hour 7 minutes) is gentle enough for beginners to enjoy hiking. For more experienced trekkers, the surrounding mountains offer more challenging routes. Immersing yourself in the scents of plants and the sounds of the wild provides a special way to disconnect from daily life.
There are several facilities to enhance your visit. Along the "Venus Line," a beautiful driving route through the Kirigamine Plateau, you will find many scenic spots. Additionally, near Lake Shirakaba, you can visit hot spring facilities such as "Koten-no-yu" to soothe your muscles after a long hike. We highly recommend visiting these nearby areas to fully relax after your nature experience.

To ensure a safe and respectful visit, please note the following: