The Genbudo Cave, a basalt cave, is formed from a total of five sinuses, which were a result of lava cooling and hardening during a volcanic activity that occurred 1.6 million years ago. In addition to the Genbudo Cave, there are also the Seiryudo, Byakkodo, Kita Shinjudo, and Minami Shinjudo caves to be explored in the park. The basalt caves are part of the San’in Kaigan UNESCO Global Geopark.
