Akiyoshidai Plateau
Akiyoshidai, located in Mine City, Yamaguchi Prefecture, is Japan’s largest karst plateau and has been designated a Special Natural Monument. This natural wonder was formed from ancient coral reefs that existed about 300 million years ago.
The vast grasslands feature a distinctive landscape of limestone pinnacles sculpted by rain over time. The striking contrast between the lush green fields and the white stones scattered across them is truly captivating. Visitors can enjoy spectacular seasonal scenery—fresh greenery in spring and silver pampas grass in autumn.
Across the plateau, you’ll find unique geological formations such as dolines (sinkholes) and unusually shaped limestone rocks, offering a glimpse into the earth’s long history. Walking trails allow you to fully appreciate these natural creations. Beneath the plateau lies the enormous Akiyoshido Cave, where you can experience the mysterious beauty of nature both above and below ground.
Akiyoshido Limestone Cave
The Akiyoshido (Shuhodo) Limestone Cave, stretching over 10 kilometers underground, is one of Japan’s largest limestone caves and has been designated a Special Natural Monument. This vast underground world, often described as an artistic natural palace, was formed over a period of about 300 million years.
The cave maintains a constant temperature of 17°C throughout the year, making it cool in summer and warm in winter. Among its remarkable features are the “Hyaku Mai Zara” (One Hundred Plates)—a series of terraced limestone formations, the “Kogane-bahira”, a 15-meter-high rock that stands majestically in the center of the cave, as well as the “Cave Mt. Fuji” and “Waterfall Basin.” Of these, Kogane-bahira is especially famous as the cave’s symbol.
A well-maintained walking path allows visitors to explore the cave comfortably in about one hour, offering a magnificent glimpse into the mysteries of nature hidden beneath the earth.