S P O T ／ SPOT-199
Oshima Island and Ominato Jinja Shrine
雄島・大湊神社おしま・おおみなとじんじゃ
An uninhabited island approximately two kilometres northwest of Tojinbo, with an area of 10.2 hectares and a perimeter of two kilometres. The entire island is composed of rhyolite of the Cenozoic Neogene Miocene epoch (approximately 13 million years old), exhibiting well-developed columnar and tabular jointing. The red-lacquered Oshima Bridge (total length 224 metres) provides access. The Ominato Jinja Shrine, with a founding tradition in the Hakuchi era (around 650 CE), is listed in the Engishiki Jinmyocho; its haiden (worship hall) and honden (main hall) are designated Important Cultural Properties of Fukui Prefecture. The island is the site of an active folk tradition: it is said that walking around the island counterclockwise brings misfortune — a 'no left-turn' prescription that remains in effect. Geologically notable features include the 'Magnetic Rock' (where the remanent magnetism of the volcanic rock disrupts compass readings) and the 'Urigari-no-mizu' (a freshwater spring near the shoreline).
H I G H L I G H T S
Highlights
- 01A geological island composed entirely of Cenozoic Neogene Miocene rhyolite (approximately 13 million years old), with well-developed columnar and tabular jointing
- 02An Engishiki-listed shrine founded in the Hakuchi era (around 650 CE): the haiden and honden are designated Important Cultural Properties of Fukui Prefecture
- 03An active folk tradition: walking around the island counterclockwise is said to bring misfortune — the 'no left-turn' prescription remains observed
- 04The red-lacquered Oshima Bridge (224 m) and the primeval forest of the sacred precinct create a striking landscape
- 05The Magnetic Rock (compass deviation from remanent volcanic magnetism) and the Urigari freshwater spring near the shoreline
A C C E S S ／ M E T A
Essentials
- Location
- Fukui Prefecture Sakai City
- Address
- 福井県坂井市三国町安島
- Fee
- 無料
- Hours
- 散策自由（大湊神社陸宮は9:00〜17:00）
- Status
- 現存（通年散策可能・大湊神社は終日参拝可）
- Official
- https://www.mikuni.org/
D E E P D I V E
Deep Dive
Religion
Religion
The principal deity is Izanagi no Mikoto. The shrine is revered for maritime safety, bountiful fishing, and good fortune, and the entire island is considered sacred ground. The approach includes 78 stone steps through ancient forest (Castanopsis sieboldii, Machilus thunbergii, Neolitsea sericea) to the haiden. The 'Oshima Matsuri' festival (annual grand festival) takes place each April, featuring a dramatic procession carrying the portable shrine to the sea and harbor. The island is said to have been free of logging for over 1,000 years.
Architecture
Architecture
Geology: The entire island consists of Cenozoic Neogene Miocene rhyolite (a high-silica volcanic rock with 71–74 wt% SiO2). K-Ar dating places it at approximately 13 million years old (13.0 ± 0.3 Ma)—a lava dome. The southern coast displays 'columnar jointing' formed by vertical cooling (resembling a honeycomb when viewed from above, contrasting with Tojinbo's upright columns). The northern coast shows 'platy jointing' from horizontal flow. 'Magnetic Rock' locations, where lightning-induced thermoremanent magnetism deflects compass needles, are also present. 'Urikachi no Mizu' is a freshwater spring near the shore—groundwater flowing through rock joints, cold even in midsummer. The Ominato Shrine main hall and haiden exhibit Momoyama-period style (cedar-shingle roof), confirmed by ridge plaques to 1621; the steep roofline with shallow eave projection accommodates Hokuriku winter winds.
Cultural Property
Cultural Property
Ominato Shrine main hall and haiden: Fukui Prefectural Important Cultural Properties. Oshima Bridge (224m red bridge): constructed approximately 90 years ago (1930s). The island is designated a Special Protection Zone of the Echizen-Kaga Coast Quasi-National Park. Its primary broad-leaved evergreen forest, said to be unlogged for over 1,000 years, is valued as a natural heritage.