01.Iwami Tatamigaura Entrance
- 2210-1 Kokubucho, Hamada, Shimane
- Regular holiday
- Available（200円 per car）
- Hamada City Tourism Association
- Free volunteer tour guides are available on Sundays and holidays (9:00 a.m.～3:00 p.m. ※excluding July～August, and December～February）
If you go through the tunnel, you can explore stratums from over 1,600 years ago where there are numerous fossils of shells and whales, and round stones shaped like stools called "nodules" that were formed by erosion. There are also a vast number of faults and sea caves that you can see. Iwami Tatamigaura became designated as a national natural monument in 1932.