Kotokunuma Swamp

Kotokunuma Swamp is a protected wetland within Nikko National Park, near the Kotoku Onsen trailhead on the hiking trail to lakes Kirikomi and Karikomi. Despite its small size (about 300 meters in circumference) and location off the beaten track, the swamp is a favorite destination of naturalists. It is sustained by the crystal-clear waters from a year-round spring, and even at the height of summer, the water temperature never exceeds 15°C. This allows baikamo, a rare aquatic wildflower that can only survive in pristine, flowing water below 15°C, to flourish and blanket the wetland with its delicate white blossoms. In autumn, the swamp is known for reflecting the surrounding mountains covered in their fall foliage of white birch and Japaneseoak. Groves of zumi, or Siebold’s crabapple, grow around the edges of the wetland; these can be easily identified by their gnarled trunks and twisted branches. Hikers and other visitors are encouraged to nclude this hidden highlight in their itinerary while taking care to preserve the delicate ecosystem of its unique environment.