Japan’s longest limestone cave. Its full extent has still yet to be fully explored, but the areas that have currently been charted are known to extend to a total length of approximately 23.7km, a truly massive scale. The cave also appears to be growing year by year. It is a labyrinthine cave that is unusual in Japan, with more than forked paths along the way. It is a source of interest to scholars and researchers and a source of excitement for those seeking a taste of adventure and exploration. It is also designated as a special natural treasure.

Only the first 500m section is open to the public, which takes approximately 40 minutes to walk along at a leisurely pace. Visitors soon get into explorer mood when they borrow helmets and torches at the entrance. Here you can truly experience what a limestone cave is all about, from the dim lighting to cold temperatures, as well as low ceilings, slippery paths and bats. It is also fun to search out some of the limestone formations that have been given names, like the “penguin,” and the “one-horned rhino.”

Come and delve into the depths of this mysterious labyrinth that still hides countless secrets inside its many chambers!