Oniiwa Park is a scenic spot in Hida-Kisogawa Quasi-National Park. It is located along the mountain stream flowing into Lake Matsuno, which is near the headstream of the Kako River. There are a lot of strange-shaped granite rocks towering along the gorge. Each rock is named according to its shape such as Usu-iwa (Mill Rock), Taro-iwa, Hasami-iwa (Scissor Rock), Byobu-iwa (Folding Screen Rock) and Gyoja-iwa (Mountain Practitioner Rock). There are three routes to walk through the park, which include “Iwato-kuguri Course,” where visitors can enjoy going through an 80-meter-long and narrow tunnel.

The name “Oni-iwa (Ogre’s Rock)” is derived from the legend that once upon a time there lived an ogre named Seki no Taro. In the park is the cave, which is believed to have been his dwelling. At the Bean-scattering Ceremony on Setsubun (February 3) held in this park, the throwers chant “Demons in! Luck in!” in stead of chanting “Demons out! Luck in!”

The granite rocks that have been eroded for tens of millions of years give fine contrast to the deep forest, where visitors can enjoy various seasonal changes including cherry blossoms in spring, fresh green in summer and crimson foliage in fall.