The name Senjōgahara translates to 'Field of the Battle,' derived from a Japanese mythological legend involving a battle between the deities of Mount Nantai and Mount Akagi.
The moor is a designated Ramsar site, recognized for its importance as a high-altitude wetland ecosystem.
In the early 20th century, the area was a site for specialized botanical research due to its unique transition from lake to marshland.
The wooden boardwalk was constructed specifically to prevent soil erosion and to protect the fragile peat moss layers beneath.
The temperature in the moor is typically 5 to 10 degrees Celsius cooler than in downtown Nikko due to its high altitude.
Senjōgahara Moor is a 400-hectare high-altitude marshland located within Nikkō National Park at an elevation of approximately 1,400 meters. The area was formed by the sediment of Lake Senjō, which originated from the eruption of Mount Nantai. It features a predominantly flat wooden boardwalk trail spanning several kilometers that crosses through tall grasses and wetlands. The ecosystem supports over 350 species of alpine plants, including the rare cotton grass and various orchids. During autumn, the moor is known for the vibrant red and gold color changes of its marsh grasses. Wildlife sightings, such as the Japanese deer and various bird species, are frequent due to the protected status of the habitat. The moor is bounded by the Yukawa River, which provides a consistent water source for the wetland vegetation.
The central observation point overlooking the vast expanse of the moor with Mount Nantai in the background.
Bring layers, as weather conditions shift rapidly in the mountains even during summer months.
Apply insect repellent before entering, as the marshland environment hosts significant mosquito and horsefly populations.
Stay strictly on the designated boardwalks to avoid damaging the protected peat vegetation.
Attempting to walk through the marsh grass off-trail, which causes permanent damage to the peat and is ecologically harmful.
Accessible year-round, though the boardwalk may be buried under deep snow during mid-winter months.
Carry out all your own trash; picking plants or disturbing wildlife is strictly prohibited.
