
Road & Geosite Conditions
Fully Accessible
- Number
- Area
- 1. Ichiburi Geosite
- 2. Oyashirazu Geosite
- 3. Omi Coast Geosite
- 4. Omigawa Jade Gorge Geosite
- 5. Imai Geosite
- 6. Itoigawa-Shizuoka Tectonic Line and Salt Trail(North) Geosite
- 7. Maikomidaira Geosite
- 8. Hashidate Gold Mine Geosite
- 9. Kotakigawa Jade Gorge Geosite
- 10. Tsugami Shindo Geosite
- 11. Himekawa Gorge Via Oito Line Geosite
- 12. Itoigawa-Shizuoka Tectonic Line and Salt Trail(South) Geosite
- 13. Himekawa Gorge Geosite
- 14. Renge Geosite
- 15. Itoigawa Coast Geosite
- 16. Miyama Park and Museums Geosite
- 17. Tsukimizunoike Geosite
- 18. Umidani Gorge Geosite
- 19. Amakazariyama Geosite
- 20. Yakeyama Geosite
- 21. Benten-iwa Geosite
- 22. Shindosan Geosite
- 23. Gongendake Geosite
- 24. Tsutsuishi Hamatokuai Geosite
- Jade
- 1. Ichiburi Geosite
- 2. Oyashirazu Geosite
- 3. Omi Coast Geosite
- 4. Omigawa Jade Gorge Geosite
- 9. Kotakigawa Jade Gorge Geosite
- 15. Itoigawa Coast Geosite
- 16. Miyama Park and Museums Geosite
- Fossa Magna
- 5. Imai Geosite
- Itoigawa-Shizuoka Tectonic Line and Salt Trail(North) Geosite
- 11. Himekawa Gorge Via Oito Line Geosite
- 12. Itoigawa-Shizuoka Tectonic Line and Salt Trail(South) Geosite
- 13. Himekawa Gorge Geosite
- 17. Tsukimizunoike Geosite
- 21. Benten-iwa Geosite
- 22. Shindosan Geosite
- 24. Tsutsuishi Hamatokuai Geosite
- Mountainous areas
- 7. Maikomidaira Geosite
- 8. Hashidate Gold Mine Geosite
- 10. Tsugami Shindo
- 14. Renge Geosite
- 18. Umidani Gorge Geosite
- 19. Amakazariyama Geosite
- 20. Yakeyama Geosite
- 23. Gongendake Geosite

The Himekawa Gorge ranges in depth from 200 to 500 meters and was formed by the intense erosion of the surrounding mountains by the Himekawa River. Along Kuzuha Pass, bordering Nagano prefecture, you can easily observe the erosion and denudation of the mountains in this ravine.
Kuzuha Pass itself, located on the west bank of the Himekawa River, was formed as a result of the collapse of Mt. Manaitayama which sits on the opposite side of the river. This plateau-like block is 150 m high from the riverbed and is 1 km by 500 m in area. This block consists of a layer of fragile Permian sedimentary rock on top of a section of clay-like breccia. We can estimate the speed of erosion of this valley through these collapses. By observing wood fossils trapped in the clay bed, we know that two collapses occurred, one 500 and the other 1000 years ago.
At the Gamaharazawa River, a tributary of the Himekawa River, a large avalanche of earth, rocks, and other debris occurred, killing 14 people. A monument was erected at the site in memory of those lost.


Collapsed geology (colluvium) at Kuzuha Pass

Bokka Horse Chestnut—Once an important landmark for travelers

Himekawa River

Gamaharazawa River

Road washed away in the Flood of July 11

Cenotaph for the Debris Flow Disaster