Akiyoshido Cave

Akiyoshido is a limestone cave beneath the Akiyoshidai karst plateau. It lies about 100 metres below the plateau and opens at its southern foot, within Akiyoshidai Quasi-National Park. The cave is a Special Natural Monument, a national designation.

The cave runs for more than 11.2 kilometres in all, the second longest in Japan. About one kilometre of it is open as a walking route, which takes about an hour one way and about 90 minutes there and back. The temperature holds at 17 degrees through the year, so the cave is cool in summer and warm in winter.

Water leaves the cave at the entrance and drops in three stages into the stream below. Formations along the route include Hyakumaizara, the hundred plates, a slope of shallow terraced pools that look like rice paddies. A lift runs between the cave and the plateau above.

In 1926 the future Emperor Showa, then still Crown Prince, explored the cave and gave it the name it carries now.

The cave holds small animals, most of them one to ten millimetres long, that have adapted to living underground. Most are white and their eyes have degenerated, and some are found only in the caves of this area. Akiyoshidai has around 420 caves altogether, with about 15,000 bats of six species.