”Ryusendo” Stalactite cave that was created by nature

Stalactite cave that was created by nature

50 years for 1cm

What is ”50 years for 1cm”? It is the speed of the growth of a stalactite hanging from the cave like an icicle. Not 50cm per year but 1cm per 50 years…. It is an unbelievably long time. Stalactite cave is a cave made by limestone that was eroded by underground water. If the stalactite took 50 years to grow 1cm, how long did it take for the cave to get to its current size? In Iwate Prefecture, there is a famous stalactite cave. It is Ryusendo located in the east in Iwaizumi city of Shimohei county. We eagerly go to the cave looking forward to the adventure.

”Ryusendo” is one of the largest stalactite caves in Japan

Ryusendo is said to be one of the top 3 stalactite caves in Japan. It was designated as the nation’s natural monument titled as ”Iwaizumi Wakkutsu (old name for Ryusendo) and bats” in 1938.
The characteristic of the cave is in the altitude difference of the highest and lowest points, about 250 meters. So there are many staircases, and you will be surprised by the depth of the cave. And to add to this, it is famous for the underground lake. They have counted multiple underground lakes and of those, 3 are open to the public. The third underground lake is 98m deep. It is rich in clear water and the view is mystical. As a matter of fact, the water has been chosen as one of the 100 best water in Japan. It is that clear.

There were people living in the cave?

Ryusendo has a stalactite cave called Ryusen Shindo (Ryusen New Cave) which was discovered in 1967. We visited there as well. We first saw the site of bats.
”They are asleep”, said Sono Yaegashi calmly as he guided us. Nevertheless, the eerie atmosphere of bats in the cave made us nervous.
According to her, there was also evidence of human life in the cave in the past, not just the bats. They found some clay potteries and bones of animals which was probably their food. ”The cave must have been more comfortable to live since the temperature does not change as much as the outside world”, she explained.
Considering the fact that it takes 50 years for the cave grow 1 centimeter, it made us wonder about the tremendous amount of time for any changes. That means the view here has probably not changed that much since those days. We don’t know what kind of people lived here in what condition, but in front of us, the vision we were sharing was the same view that hadn’t changed for thousands of years. It was a space where we could feel the grandness of nature with our skin.


Kannari-1-1 Iwaizumi, Iwaizumi-chō, Shimohei-gun, Iwate Prefecture
URL http://www.iwate-ryusendo.jp/en/