Iwaya Iwakage Site
岩屋岩蔭遺跡
A Jomon-period site among giant boulders in the mountains of Kanayama Town, said to have been an ancient solar calendar observatory. Sunlight through gaps in the stones can be observed.
The Iwaya Iwakage Site is located at Iwase in Kanayama Town, Gero. Three giant boulders support one another to form a rock shelter, where early Jomon-period pottery and stone tools have been excavated. Researchers believe the gaps between the boulders were a 'solar calendar' device used by ancient people to observe the sun and determine the seasons. At the summer and winter solstices and around the spring and autumn equinoxes, sunlight falls on specific spots. In recent years it has attracted attention as a power spot, and a research group in the nearby Kanayama boulder group gives regular talks on the observation results. It is free to visit and about 30 minutes by car from Gero, near Iwaya Dam.
Opening hours
All day
Nearby sights
- Nakayama Shichiri Gorge
- Hida-Kanayama Kinkotsu Alleys
- Gero Funsen-ike & Hida River
- Yokotani Gorge
- Kaeru Shrine
- Gero Museum of Hot Springs
- Onsen-ji Temple
- Gero Onsen Town & Yumeguri