A limestone cave with a deep blue, clear and tranquil lake of mystery

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Passing through the limestone cave and the roosts of bats, you go further deeper until you finally reach the underground lake which boasts the one of the world’s clearest and deepest waters as it shines like a deep blue jewel.
Business Hours
Saturday ( 8:30 AM ~ 5:0 PM )
Sunday ( 8:30 AM ~ 5:0 PM )
Weekdays ( 8:30 AM ~ 5:0 PM )

May-September 8:30am-6:00pm October-April 8:30am-5:00pm [close] No holidays In cases where it may be difficult to open the cave due to increased water levels from snow melt or other weather conditions, Ryusendo will be closed. Only the New Ryusendo Museum will be open.
Adult: 1,000 YEN
Children: 500 YEN
Kannari-1-1 Iwaizumi, Iwaizumi-chō, Shimohei-gun, Iwate-ken

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A beautiful limestone cave with an underground lake that shines Dragon Blue

Ryusendo, which counts itself as one of Japan’s Three Major Limestone Caves, is famous for its underground lake which glows an eye-opening lovely blue color and has some of the world’s deepest and clearest waters. Up to now, the cave is known to be 3600m deep of which 700m are open to the public, but there are ongoing investigations, and one theory goes that it may exceed 5000m. Also, there are 8 underground lakes that have been discovered of which 3 are open to the public. Precious animals thrive in Ryusendo, and the bats that live in the cave are protected as nationally-designated Natural Monuments along with Ryusendo itself.

Tour the cave with the feeling of an underground explorer aiming for the mysterious lake

Inside Ryusendo is a different world. Even in summer, the temperature inside is a cool 10℃, and the limestone corridors whose rocks of complicated shape seem almost like natural forms of art created by eternity continue on down the cave. The No. 1 underground lake at a depth of 35m and the No. 2 lake at 38m have a clear blue color that has been called Dragon Blue and boast a clarity that is one of the most prominent in the world. At the very bottom is the No. 3 lake that has a depth of 93m. The slightly wider space in the cave known as Gekkyuden is illuminated with LEDs in 5 colors, so that it provides a mysterious atmosphere to amaze the visitors.

Seasonal customary events to further increase enjoyment in the cave

Ryusendo has been praised for its planned seasonal events. The Winter Illumination in December has the cave interior and the grounds all done up in lights to shine romantically. Also, during the Bat Watching which is held from December to March, guides show you places where you can observe bats hibernating. Also, there are events such as treasure hunting, concerts held in the cave, photograph exhibitions, and many other attractive plans that bring the cave alive.

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