Shuzenji Spa Geosite offers a view of the thick pumice layer from submarine volcanism, the Asahidaki Falls (a volcanic neck), besides the historical landscape of the Shuzenji Hot Spring Town. Tokko-no-yu Spa is a famous landmark. Today, visitors can use this hot spring as a footbath.
The basalt complex that rose from under the ground and pierced through the thick pumice layer that had accumulated around Shuzenji Spa is known as the Asahidaki Falls Basalt. The lava that penetrated the pumice layer contracted in the process of cooling down and solidifying, creating the column-shaped rocks called "columnar joints."