Ryugado Cave is located on Mount Sampo in Kōchi Prefecture on the island of Shikoku, Japan. The facility is open to the public and includes a sightseeing route (a relatively easy course, which I took) and an adventure route (with a guide through rougher areas of the caves).
In addition to the cave itself, the facility also houses a rare bird center, a museum, a gift shop, and a restaurant.

SOURCE: Entrance to Ryugado Cave (Kōchi, Kōchi Prefecture, Shikoku, Japan); photographed by Stephen J. Danko on 24 April 2019.

SOURCE: Woods Around Ryugado Cave (Kōchi, Kōchi Prefecture, Shikoku, Japan); photographed by Stephen J. Danko on 24 April 2019.

SOURCE: Statue Outside Ryugado Cave (Kōchi, Kōchi Prefecture, Shikoku, Japan); photographed by Stephen J. Danko on 24 April 2019.

SOURCE: Shrine Inside Ryugado Cave (Kōchi, Kōchi Prefecture, Shikoku, Japan); photographed by Stephen J. Danko on 24 April 2019.

SOURCE: Monument Inside Ryugado Cave (Kōchi, Kōchi Prefecture, Shikoku, Japan); photographed by Stephen J. Danko on 24 April 2019.
Copyright © 2019 by Stephen J. Danko