Ryusendo

Ryusendo Cave (, Rysend) tops the list of the most beautiful caves in Japan. It is a large limestone cave in Iwaizumi Town, Iwate Prefecture, and is considered one of Japan's three famous limestone caverns. The caves are thought to extend approximately 5000 meters below the slope, with only roughly 3500 meters investigated since studies began in the 1920s. Large amounts of clear, blue water flow from the cave's depths, generating an underwater river and four underground lakes in the caverns. Fresh spring water creates deep underground lakes in the cave; the third lake, with a depth of 98 meters and stunning emerald-green water, is the most remarkable. The fourth lake is Japan's deepest underground lake (120 meters) and one of the world's most transparent lakes, albeit it is not included in the tour. There are also unusual formations like stalactites and stalagmites, as well as rare long-eared bats can be seen. For the first time in 41 years, underwater research beyond the third lake was done in December 2009.

Ryusendo Cave is exposed to the public for about 700 meters and is accessible via elevated walkways, bridges, and stairs. The trail through Ryusendo is well-developed and easy to navigate, despite the fact that it is daring. The caves are rather vast, with only moderate constrictions at times. On their route to the underground lakes further back, visitors can stroll along the underground river that flows through the cave entrance and explore various open caverns and lofty vaulted galleries.

Opening Hours: 8:30am-6pm
Open every day of the year
Admission： Adult- ¥1,000, Elementary, jr. high student- ¥500, Child- Free
Address: 1-1 Kaminari, Iwaizumi-aza, Iwaizumi-cho, Iwate (Google Map)