Ryusendo Cave

One of the three largest limestone caves in Japan and designated as a national natural monument.

Fresh water gushing from deep within the caves forms deep underground lakes at several locations, with the third underground lake at a depth of 98 meters. The third underground lake is 98 meters deep, while the fourth underground lake, which is not yet open to the public, is the deepest in Japan at 120 meters.

The clarity of the water is one of the highest in the world.
The total length of the lakes is approximately 1,200 meters (the actual total length is said to be more than 2.5 km or 5 km).

Five species of small winged bats have been confirmed to inhabit the cave: kikugashira bats, kokikugashira bats, peach bats, rabbit bats, and tengu bats.

The water in Ryusendo is famous for being one of the clearest in the world, and this is due to the water from the streams that go deep underground and gush out in the underground lake.

The water is filtered by high-quality humus soil and also has a strong taste because of the large amount of dissolved calcium in the ground. It is selected as one of the 100 best waters as water from the Ryusendo underground lake.

The Ryusendo Festival is held in the area. On the eve of the festival, a big sale, flea market, food stall village, and local entertainment will be held in the Ureira shopping street. On the day of the festival, the Ryusendo Festival is held in the Ryusendo-do Cave parkland, with sales of the town’s specialties, performances of local entertainment, and a lucky rice cake making event with prizes, attracting many people every year.