Japanese White Pine Monument
The Japanese White Pine Monument is located by the forest road. Visitors negotiating the narrow path behind the monument come to a beautiful gorge of peridotite rock known as lherzolite, which has high pyroxene content. Some lherzolite rocks have reddish-purple layers resulting from the breakdown of a mineral known as garnet, which suggests that the Horoman peridotites were once located 50 to 60 km under the earth's surface.
Kitagoyo (P. parviflora var. pentaphylla) trees cover the mountainside across the river. This northern limit of their habitat was designated as a Natural Monument of Japan in 1943, and the surrounding area is also known as Hokkaido's lowest-altitude habitat of the Japanese pika.