Dragon river cave: MAR to NOV daily 8:30-17, DEC to FEB daily 8:30-16:30.
Museum: MAR to NOV daily 8:30-16:50, DEC to FEB daily 8:30-16:20.
Cave Trekking tours: after appointment. 
Adults JPY 1000, High School JPY 650, Elemetary School JPY 500.
Groups (30+): Adults JPY 920, High School JPY 550, Elemetary School JPY 400.
Cave Trekking tours: Adults JPY 1000, High School JPY 1000, younger children not allowed.
Bird station: free.
|Light:||Incandescent Electric Light System|
Cave Trekking tours: D=90 min.
|Address:||Ryugadou Preservation Group, 782-0005 Sakakawa, Tosayamada-cho, Kami-gun, Kohchi Prefecture, Tel: +81-887-53-2144, Fax: +81-887-53-2145.|
|As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.
|1934||designated a national natural monument and a national historic site by the Japanese government.|
龍河洞 (Dragon River Cave) has fine speleothems and numerous archaeological remains. Around the cave entrance pottery from the Yayoi Period (300BC-300AD) was found. There were shards, animal bones, and shells in one corner of the entrance, and a water jar to collect water dripping from above in the other corner. The archaeological remains are on display in a small museum at the cave entrance. There is also a Onagadori bird station and both, museum and bird station are free.
Quite exceptional is the Kami-no-tubo (God's Jar), which is a Yayoi-style earthenware bottle with a round body and a conical neck. It was obviously placed on a ledge in the flowstone, probably to collect water, and then forgotten. Today the whole bottle is covered by at least 1 cm of flowstone and looks like it was created together with the stone, hence the name. Actually it is quite natural that objects are covered by limestone, but in 1937 someone placed another jar on the flowstone beneath the bottle as an experiment. The result is as normal as it is spectacular, the jar is completely covered by limestone.
In the maze-like cave more than 100 species have been counted so far. Beneath cave visitors like bats there are true cave animals like blind crabs.
The cave offers cave trekking tours, locally called Bouken or Adventure Course. Participants get helmets and headlamps. The tours are possible only after appointment.