Ryusendo Cave

Ryusendo Cave locates in the northern region of Iwate prefecture. It is one of Japan’s three famous limestone caves, and is designated as a national natural monument. The bats that live in the cave, too, are national natural monuments.
The depth of the cave is still undiscovered, and as of 2018, it is said to be 3,600 meters deep. However, it is said to be over 5,000 meters deep. 700 meters of it is open to the public.
There is a special spring in the cave, known as the “Spring of Longevity”, and it is said that drinking its water will prolong your life by three years. With many other springs, underground lakes and more, there are tons to see inside Ryusendo Cave.