Yashima Mire (Yashimagaura)

Overview & Charm

Yashima Mire (Yashimagaura) 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 an area of 43.2 hectares, its history is estimated to be as old as 12,000 years. Designated as a National Natural Monument in 1939, the site holds immense academic and cultural value. The landscape, characterized by diverse plant life including various species of Sphagnum moss, harmonizes beautifully with the surrounding mountains and the deep blue sky, offering a deeply moving experience for all visitors.

History & Cultural Background

This wetland has been shaped by the natural processes of antiquity. The peat layer reaches a thickness of 8.05 meters, with organic matter accumulated over millennia supporting a rich and delicate ecosystem. Historically, the area has maintained an incredibly diverse flora, including 18 different types of Sphagnum moss. The local community has lived alongside this nature for generations, and today, the wetland is cherished as an iconic natural landscape of the Kirigamine Plateau, protected by many hikers and nature enthusiasts.

Main Highlights

The greatest charm of Yashima Mire lies in its vibrant seasonal transformations. In June, the landscape is painted with the bright colors of the Rengetutsuji (Japanese Andromeda), and in July, the Nikko Kisuge (Daylil) blooms in mass, enveloping the entire wetland in vivid color. Visitors can also experience the sounds of nature, such as the calls of the Schlegel's tree frog, which is featured in the Ministry of the Environment's '100 Soundscapes of Japan.' The walking course circling the wetland (approx. 3.8km) is well-maintained and relatively flat, offering a panoramic view of the surrounding mountains.

Seasonal Recommendations

The expression of the wetland changes dramatically depending on the season:

• *Spring to Summer (May–August)**: The peak blooming season. The sight of Rengetutsuji in June and Nikko Kisuge in July is a once-in-a-lifetime view. The greenery is lush and full of life.
• *Autumn**: The grasslands turn to a beautiful golden hue, making it a perfect time for hiking amidst crisp, clear air and autumn colors.
• *Winter**: While the plateau experiences harsh weather, the silent, snow-covered landscape offers a unique and serene beauty. However, please be cautious regarding weather and road conditions.

Activities & Experiences

There are various ways to connect with nature here. The well-maintained loop course (approx. 1 hour 7 minutes) is accessible even for beginners. For more experienced trekkers, the surrounding mountains offer more challenging paths. Immersing your senses in the scents of plants and the sounds of the plateau provides a special escape from daily life.

Surrounding Area

The area around Yashima Mire is rich with tourism facilities. The 'Venus Line,' a beautiful driving route through the Kirigamine Plateau, offers many scenic spots. Additionally, near Lake Shirabaka, you can find hot spring facilities like 'Koten-no-Yu,' where you can soothe your muscles after a long hike. We highly recommend combining your nature walk with a relaxing soak in a local onsen.

Essentials & Etiquette

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

• *Clothing**: Temperatures fluctuate significantly on the plateau. Even in summer, bring a light jacket and wear sturdy walking or trekking shoes.
• *Payment**: We recommend carrying both cash and credit cards for nearby facilities and parking.
• *Language**: While the area is well-maintained, most signage is in Japanese. It is helpful to check maps or information in advance.
• *Reservations**: No reservations are required for the Yashima Plateau parking area, though it may be crowded.
• *Manners**: To protect the delicate ecosystem, please stay on the designated paths. Do not pick plants or leave any trash behind.