ABOUT
About this spot
"Ikura-do," designated a Natural Monument of Okayama Prefecture, is one of Japan's finest limestone caves, located in the limestone region of Ikura, Niimi. The cave, about 1,200 meters long, is cool in summer and warm in winter, so it can be enjoyed comfortably all year round. Inside, named highlights shaped over tens of thousands of years are scattered throughout, including "Seto no Umi," "Niji no Tani," and "Sphinx." With an elevation difference of about 90 meters, the up-and-down course gives you the thrill of an underground expedition. The roughly 50-meter "Jiku no Taki" waterfall also tumbles down inside, with a power that ranks among the largest cave waterfalls in Japan. Don't miss the 240-meter limestone cliffs outside the cave and the canyon beauty of "Ikura Falls," which flows into the Takahashi River. As a leading sightseeing spot of Niimi, it is ideal for making family memories, an active day out with friends, or a solo trip to quietly feel the wonders of nature. The surrounding walking paths also offer seasonal scenery, so please be sure to visit.
Last updated March 28, 2026