Akiyoshido Cave

Akiyoshido is Japan's largest limestone cave, with a total mapped length exceeding 10 kilometers, though approximately one kilometer of well-lit walkways are open to the public. The cave sits beneath the Akiyoshidai karst plateau, the largest karst landscape in Japan, and was formed over 300,000 years ago by the dissolution of ancient coral reef limestone. Inside, visitors encounter extraordinary formations including Hyakumaizara, a series of terraced rimstone pools resembling rice paddies that cascade down a slope, and the towering Kogane-bashira golden pillar stalagmite rising 15 meters from the cave floor. The cave maintains a constant temperature of around 17 degrees Celsius year-round, making it a comfortable visit in any season. An elevator near the midpoint connects to the Akiyoshidai plateau above, allowing visitors to combine the underground cave tour with a walk across the vast grassland dotted with exposed limestone pinnacles. The cave is designated as a Special Natural Monument of Japan and is one of the most visited caves in the country.