Spelunking is the exploration of what, especially as a hobby?
River cave Dry cave Cave Natural cave World's deepest cave Sacred cave Caves Fossil cave Primary caves Collapse cave Cave system Cave systems Dripstone cave Cave records Karst Cave Primary cave Caverns Collapse cavern Cave complex Cavern Natural caves Cave (natural) Water cave
sacred cave river cave primary caves caverns cave natural cave records collapse cave water cave cave systems collapse cavern dripstone cave fossil cave dry cave primary cave cave complex cave caves world s deepest cave natural caves karst cave natural cave cave system cavern
caves
WikipediaEntity
Caves