Oku-Nikko: Nature
The area from Lake Chuzenji to Lake Yuno is called Oku-Nikko. At between 1,300 and 1,500 meters in elevation, it is high above the rest of Nikko, and its abundant flora and fauna are more typical of the Japanese highlands.
The magnificent scene of the sacred Mt. Nantai reflected on Lake Chuzenji greets visitors once they crest the summit of the Iroha Slope. Nearby is Kegon Falls, which is one of Japan’s three most beautiful waterfalls, with a large water flow cascading down a nearly 100-meter drop. There are two other waterfalls—Nikko Ryuzu Falls and Yudaki Falls—located in Oku-Nikko.
Further north are the marshlands of Senjogahara and Odashirogahara, the Yu River, and Lake Yuno. The marshes are collectively registered as Wetlands of International Importance under the Ramsar Convention and are a protected habitat for many kinds of vegetation and wild birds. Visitors can enjoy hiking and birdwatching from the boardwalks that run through parts of the marsh.
Continuing north is Yumoto Onsen, a village of hot-springs inns that stretches out along the banks of Lake Yuno. Yumoto Onsen has a history of more than 1,200 years and its springs have the fourth-highest concentration of sulfur of any hot springs in Japan. The Yumoto Visitor Center and Nikko Natural History Museum are located near the lake and offer the latest information on seasonal activities in the area.