This popular cave has some interesting stalactites and stalagmites, and traces of prehistoric habitation. The route gets quite steep in places. Visitors on a standard ticket will see about 1km of the 4km cave. Advance reservations and an additional ¥1000 are required for the bōken kōsu (adventure course; 冒険コース), where you get to don a helmet and overalls and follow a guide for a 90-minute exploration of the inner reaches of the cave. The adventure course is limited to Japanese-speakers.
There are five buses a day to Ryūga-dō from Tosa-Yamada Station (¥440, 20 minutes). Tosa-Yamada Station is 30 minutes from Kōchi by local train (¥360), or 10 minutes by tokkyū (limited-express train; ¥1210).