Everywhere, everywhere,
Overwhelming nature.

― Special Natural Monument - Akiyoshidai ―

Akiyoshidai Quasi-National Park, located in Mine City, Yamaguchi Prefecture, has a total area of ​​4,502 hectares.
The karst plateau, with its white limestone rock surface, is one of the largest in Japan.


Breathe on the karst plateau 350 million years ago Earth memory

Akiyoshidai is the largest karst landform in Japan, located in the Midwest of Yamaguchi Prefecture. The gentle plateau at an altitude of about 300m is surrounded by steep cliffs and plains spreading at the foot. The beginning of Akiyoshidai was born as a coral reef in the warm southern sea. Yes, Akiyoshidai was originally the sea. Coral reefs become limestone rocks over time. The coral reefs become limestone and repeat. After a long period of about 350 million years, the thickness of the limestone that moved while accumulating from the sea to the mountain ranges from 500m to 1,000m. There, rainwater flowed and limestone melted over a long period of time, and it became the current terrain. The beauty of Akiyoshidai, which was completed over a long period of time than human history, is a work of nature.


Akiyoshidai Limestone

Rocks protruding all over Akiyoshidai that look like a flock of sheep. It is a coral reef limestone that was buried deep underground, and rose to the outside due to plate movement. As you can see, the limestone of Akiyoshidai is said to contain a lot of fossils of organisms that lived in the sea during the Paleozoic era. Akiyoshidai is a karst land made by melting limestone. Limestone is mainly made of calcium carbonate. Since limestone is easily soluble in water, rain falling on the limestone plateau contains carbon dioxide in the air and becomes weakly acidic water. It also contains a lot of carbon dioxide as it passes through the soil, and when this water comes into contact with limestone, it causes a chemical reaction that gradually dissolves the limestone. The earth is still alive, repeating and repeating it.


Recesses scattered on the ground

Where the ground around the karst plateau is mortar-shaped, this is called a dorine. The karst landform is originally made of limestone, with the coral reef fossilized and raised. As a result, the erosion by water is severe, and the surface collapses as the limestone cave is formed. Water that flows over the surface penetrates underground through limestone fissures, and erosion is repeated, forming depressions and limestone cave forever. The hole formed by this sinking is called Dorine, the one where multiple Dorine grows and connects is Uvale, and the lowland where it has become huge is called Polje.

please note

Please be careful about Doline when walking around Akiyoshidai. If it falls, it is completely dark and the bottom is as deep as possible, so it doesn't come up. When walking, walk along the road and stay away from fences. Also, keep away from places where vines (such as kudzu) are unnaturally located in the hollows.

The four seasons of Akiyoshidai

The vast karst plateau and rich natural beauty.
Visit the four seasons to explore the wind, the sky, rocks and creatures.

  • 春
  • 夏
  • 秋
  • 冬

"Know" "See"
"I feel it"


Mine Akiyoshidai Geo Tour

Just enjoying the scenery is a waste! Suggest how to enjoy Mine Akiyoshidai! Let's go out with the guide!


Let's go to the limestone cave Let's go to the limestone cave

Three caves under the land of Akiyoshidai. Let's go see the artistic beauty that is not an exaggeration to say that it is a natural art object.


Enjoy sports

Enjoy trail running, trekking and cycling in spectacular scenery and beautiful locations!

Akiyoshidai night

Akiyoshidai is also a place with a beautiful starry sky.
The night sky you see in a 360-degree panoramic landscape with no obstructions
A beauty that is fantastic as if you have lost your way into another world and that you are likely to be sucked in.
All year round, you can enjoy a wonderful starry sky if the weather is good.
Surrounded by the stars and the clear starry sky as far as the eye can see,
Please try it.


Mine Akiyoshidai Geopark

Geopark is a word that combines "Earth and Earth (Geo)" and "Park (Park)". It means "Earth Park". A place where you can do it. Akiyoshidai Geopark is one of the Japan Geoparks approved by the Japan Geopark Committee.


Mine Akiyoshidai Geo Tour

At the Geopark, locals can guide you on a journey to find "greatness" (called a "geo tour"). One of the most recommended tours with Akiyoshidai Certified Guide is the trekking along the grassland of Akiyoshidai and the course to explore the limestone cave. Exploration of the cave can be enjoyed anytime except during heavy rains.