Main
Big photo
Wikipedia: A cave or cavern is a natural underground space large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and grottos. Speleology is the science of exploration and study of all aspects of caves and the environment which surrounds the caves.
![[Exploring a lava tube in Hawaii.]](http://images.ookaboo.com/photo/s/Hawaiian_lava_tube_s.jpg "Exploring a lava tube in Hawaii.")
|
![[Karst cave with underground river exiting at Tolantongo, Mexico.]](http://images.ookaboo.com/photo/s/RiverExitTolantongo_s.jpg "Karst cave with underground river exiting at Tolantongo, Mexico.")
|
 from Dave Bunnell |
 from :en:Thelmadatter |
Is there something wrong with this topic? See our policies on offensive content; if you see something wrong, contact us.
