Akiyoshido Cave: A Great Limestone Cave Below Akiyoshidai
Akiyoshido Cave (秋芳洞, Akiyoshi-dō) is a limestone cave in Shuho-cho Akiyoshi, Mine City, Yamaguchi Prefecture, designated a national Natural Monument in 1922 and raised to a Special Natural Monument in 1952.
Its mouth opens into the Hirotani polje at the southern foot of the Akiyoshidai plateau, and a strong flow of groundwater pours out of it. Mine City gives the entrance as 20 metres high and 8 metres wide. Figures for the length differ: the Mine City Board of Education gives about 8.8 kilometres, while the official Akiyoshidai website says more than 11.2 kilometres, second in Japan. About 1 kilometre of Akiyoshido Cave is open as a show-cave route.
It was once known as Takiana, a place where a god lived and which people avoided. In 1926 the Crown Prince, later Emperor Showa, visited and gave the cave its present name.
Why It Was Designated
The Agency for Cultural Affairs describes Akiyoshido as a cave formed by the erosion and dissolution of limestone and the largest limestone cave in Japan, of particularly high scientific value. The 1922 designation note also cites large, intact stalactites and stalagmites, carbonate deposits in many shapes, and an underground stream.
According to Mine City, the cave took shape over about a million years of dissolution by groundwater, a falling water table, deposits of sand and gravel, roof collapses and the growth of cave formations. Akiyoshidai holds more than 400 limestone caves, and Akiyoshido is by far the largest among them.
The cave also supports a notable fauna: 6 species of bats, including the greater horseshoe bat, eyeless ground beetles, and groundwater animals such as a blind amphipod and a tiny cave snail named for Akiyoshi.
What to Look For
The great chamber of Senjojiki is the cave at its most spacious. Mine City gives it as 30 metres high and 100 metres wide, widening to 200 metres at its broadest.
The other highlight is Hyakumaizara, the "hundred plates": tiers of rimstone pools whose rims were built up by lime-laden water. Mine City calls the view unmatched in Japan or abroad.
The temperature inside Akiyoshido Cave stays at about 17°C all year. Allow about 60 minutes one way along the show route, or about 90 minutes there and back. A lift partway along takes visitors up to the Akiyoshidai plateau.
Visiting Akiyoshido Cave
Admission runs from 9:00 a.m. to 4:30 p.m. in the regular season and until 5:30 p.m. from 1 July to 30 September, every day of the year. Fees vary by season under a scheme revised in April 2026: adults pay 1,600 yen normally, 1,900 yen in peak periods and 1,350 yen from December to February. Wheelchairs can be borrowed free at the Akiyoshidai tourist centre; check in advance which areas they can reach.
By public transport, take a bus from JR Shin-Yamaguchi Station to the Akiyoshido stop, about 40 minutes. By car it is about 5 minutes from the Akiyoshidai interchange on the Ogori-Hagi Road; the municipal car parks at the main entrance charge 500 yen, while those at the Kurotani and lift entrances are free. Paid guides can be booked.
Filming other than for personal use requires consultation with the Akiyoshidai Museum of Natural History. The path can be wet, so wear shoes with a good grip.
Q&A
- How long is Akiyoshido Cave?
- Sources differ: the Mine City Board of Education gives about 8.8 kilometres, and the official Akiyoshidai website more than 11.2 kilometres. About 1 kilometre is open as the show-cave route.
- When did Akiyoshido Cave become a Special Natural Monument?
- It was designated a Natural Monument on 8 March 1922 and raised to a Special Natural Monument on 29 March 1952.
- What are the opening hours and admission fees for Akiyoshido Cave?
- Adults pay 1,600 yen normally, 1,900 yen in peak periods and 1,350 yen in the off-season. Admission is from 9:00 a.m. to 4:30 p.m. in the regular season and until 5:30 p.m. from July to September, every day.
- Is it cold inside Akiyoshido Cave?
- The temperature stays at about 17°C all year, cool in summer and mild in winter.
- Where does the name Akiyoshido Cave come from?
- It was formerly called Takiana. The present name was given when the Crown Prince, later Emperor Showa, visited in 1926.
Basic Information
| Name | Akiyoshido Cave (秋芳洞) |
|---|---|
| Location | Shuho-cho Akiyoshi, Mine City, Yamaguchi Prefecture |
| Designation | Special Natural Monument |
| Year Designated | Natural Monument 1922/3/8 (Taisho 11); Special Natural Monument 1952/3/29 (Showa 27) |
| Quantity | 1 site |
| Dimensions | About 8.8 kilometres long (Mine City Board of Education); over 11.2 kilometres (official Akiyoshidai website); show route about 1 kilometre |
| Owner | Managed by Mine City |
| Public Access | Admission 9:00 a.m. to 4:30 p.m. (regular season), open daily, fee charged |
References
- Agency for Cultural Affairs Database: Akiyoshido (Japanese)
- https://kunishitei.bunka.go.jp/bsys/maindetails/401/2364
- Cultural Heritage Online: Akiyoshido (Japanese)
- https://online.bunka.go.jp/heritages/detail/139487
- Mine City: Akiyoshido (Japanese)
- https://www2.city.mine.lg.jp/soshiki/kyoiku/hogoka/bunkazai/bunkazai/kunishitei/tokubetsu/1537.html
- Akiyoshidai official website: Akiyoshido (Japanese)
- https://akiyoshidai-park.com/spot/akiyoshi-do.html
- Mine City Tourism Association: Akiyoshidai (Japanese)
- https://karusuto.com/spot/akiyoshidai/
Last verified: 2026.09.27