Mystical view! Iwate prefecture’s Ryusendo cave has dragon blue underground lakes

Still being explored... A giant limestone cave under the ground

Ryusendo cave is located in Ureira mountain in Iwaizumi village, part of Iwate prefecture. It is extremely big and so far over 3500 meters have been confirmed to exist. Exploration is still ongoing and the expectation is that the cave is over 5000-meter long. Only about 700 meters are open to the public, but the deeper you go, the stronger the feeling of walking underground becomes. The temperature inside the cave is always around 10 degrees. In the winter inside is warmer than outside, while in the summer walking there wearing short sleeves feels cold. It is recommended to bring something to put on for the cave. About 5 species of bats live there, such as the tube-nosed bat and the long-eared bat. If you’re lucky, you might even see them. In cases of big rain or during the snow thaw in the spring, the cave gets filled with water and is temporarily closed. Check the official information first before visiting it.

Access to Ryusendo Public transport: JR Morioka station, JR bus to Ryusendo, get off at the last stop (4 round-trip buses per day) Car: Tohoku highway, Hanamaki IC, route 46, route 455, through route 7 for about 88 kilometers

The water limestone cave Ryusendo

After you enter the cave and walk for a bit, you will reach “Chomei no fuchi” (Long-life abyss). The water that springs from Ureira mountain flows through the cave and goes outside to become Shimizu river. Since the water level changes, its level inside the cave is used for reference. The water in Ryusendo and its underground caves is filtrated by the limestone and is therefore very transparent, mildly alkaline and rich in calcium. It has been called “long-life water” since ancient times, and in 1985 it was added to the list of Meisui Hyakusen (a selection of 100 springs, rivers, etc. notable for their quality). There is a place to drink fresh water at the entrance of the cave.

Various stalactite shapes in the impressive Hyakken corridor

After “Chomei no fuchi” you continue to the “Hyakken roka” corridor. It is a narrow path with a high ceiling that goes straight. On either side you see the overwhelming rising walls (on the photo above). Walking along this path makes you feel you’re going to the depths of the Earth.

Upon exiting Hyakken corridor, you come across Tsukimiya-den, the widest open space in Ryusendo cave. There are many different stalactites here, and I will now introduce some of them: “Otonashi no taki” (Silent waterfall) – water flows down this stalactite all the time making it look like a real waterfall “Kameiwa” (Turtle rock) – in the shape of a turtle “Mamori shishi” (Guardian lion) – looks like a lion seen from the side “Ojizo-sama” – resembles a real Ojizo-sama (Buddhist deity) because of its red bib These are only some of the stalactites. One is surprised by the peculiar shapes made by nature.

Some of the world’s most transparent underground lakes

There are 7 known underground lakes in Ryusendo cave. All of them are formed by the water springing from Ureira mountain. The first three lakes are open to the public. Their transparent clear blue is unique and called “dragon blue”. Moreover, their depth is quite surprising:

First lake: 35 meters, second lake: 38 meters, third lake: 98 meters.

The fourth lake, which is not open to the public, is 120-meter deep! One cannot even imagine how many years must have passed for the formation of such a big cave.

The third lake (on the photo above) is the farthest in the publicly open part of the cave. Its transparency stretches to 41.5 meters, making it the most transparent underground lake in the world. Looking at the water hypnotizes you as if you’re about to be absorbed by the lake. Maybe somewhere deep inside the lake a real dragon lives.

Seen from this angle it is a real underground lake!

After the third lake you have to climb 270 stairs. Alternatively, you can return to the entrance. The elevation difference of Ryusendo cave is 250 meters. Of course that doesn’t apply to the publicly open area, but there is still some 10-meter difference with above ground.

After you climb the stairs you reach Miharatoge and the observatory of the first lake. Actually, it is an observatory where you can see the lake from above. Even if you don’t have a fear of heights, it is still a little scary. On the photo above you see the first lake from a few steps before the observatory after Miharatoge. One can understand how deep Ryusendo cave is from this photo. Be careful not to drop your camera or cell phone.