The largest limestone cave in Japan, with a total length of 10km, and extends deep down to 100m underground. Inside the cave is bright and illuminated, and can be visited from three entrances. The temperature inside the cave is 17℃ regardless of the season, so you can explore in comfort. Moreover, the artistry wrought by nature, such as the hanging stalactites, the Maria Goddess of Mercy, and the giant stalactites is truly overwhelming in scale.