Japan Heritage story
Iwami's volcanoes: Jomon forest and silver mountain in Oda
石見の火山が伝える悠久の歴史
Walk down a staircase underground in Oda, Shimane, and giant trees tower over you, buried upright by Mount Sanbe's eruption 4,000 years ago. Volcanoes here also created the silver of Iwami Ginzan, once famous worldwide, and the rich soil, hot springs and stone that local life depends on.
Key facts
- Theme
- Sea and waterside, Forests and timber, Mines and minerals
- Era
- Jōmon, Edo
- Region
- Chugoku
- Official name in Japanese
- 石見の火山が伝える悠久の歴史
- Official subtitle in Japanese
- ～”縄文の森” ”銀の山”と出逢える旅へ～
- Official area (in Japanese)
- 島根県（大田市）
The story
About 4,000 years ago, an eruption of Mount Sanbe buried a Jomon forest in ash and mud. Around 30 trees, such as Japanese cedar and horse chestnut, still stand where they grew. In the underground hall of the Sanbe Azukihara Buried Forest, trunks rise more than 10 m, the thickest needing four adults to hug it, and you can still smell the wood. Above ground, Sanbe's gentle volcanic slopes became pasture for 3,000 cattle in the Meiji era, and its soil grows fragrant Sanbe soba.
Much older eruptions left even bigger gifts. About 1.5 million years ago, hot water from magma under the Oe-Takayama volcano turned rock into silver ore, creating Iwami Ginzan, marked on 16th-century European maps. At its peak nearly 20,000 people lived in the mining town. Undersea volcanoes 15 million years ago laid down green tuff, cut for stone since the Muromachi period and still used for steps because it is not slippery.
What to see
- Sanbe Azukihara Buried Forest: Jomon trees standing in an underground hall.Google Maps 三瓶小豆原埋没林公園 (opens in a new tab)
- Okubo Mabu: one of Iwami Ginzan's largest mine tunnels, 15 m wide and 20 m high.Google Maps 大久保間歩 (opens in a new tab)
- Kotogahama: a curved beach of singing sand, thought to be an old volcanic crater.Google Maps 琴ヶ浜 大田市 (opens in a new tab)
- Mononobe Shrine: Iwami's leading shrine, facing sacred Mount Sanbe.Google Maps 物部神社 (opens in a new tab)
Plan your trip with the Shimane prefecture guide, see more nature or relax at an onsen.
Good to know
- Try Sanbe soba, grown in volcanic soil and known for its aroma.
- Soak at Sanbe Onsen on the mountain's slopes after a walk.
- Walk on Kotogahama's sand and listen for it to squeak.
Questions travellers ask
How old are the buried trees?
They were buried by Mount Sanbe's eruption about 4,000 years ago, in the Jomon period.
How did volcanoes create Iwami Ginzan?
About 1.5 million years ago, silver-bearing hot water rose from magma under the Oe-Takayama volcano and turned the rock into silver ore.
Where it comes from
More heritage stories from the same area
- Esashi: the herring town that outshone Edo
- Fukiya: the birthplace of Japan Red
- Iwami kagura: gods and demons dance the old myths
- Izumo: the sacred land where the sun sets
- Izumo's tatara: a thousand years of making iron
- Kitamaebune: the merchant ships that made Japan's port towns rich
- Masuda: a medieval masterpiece of Japan
- Tsuwano: walk into a book of 100 old paintings
Local foods from the same area
Crafts from the same area
Sources
We checked the facts on this page against these sources.