Cave

A cave or cavern is a natural void under the Earth's surface.^[1] Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance underground (such as rock shelters). Caves which extend further underground than the opening is wide are called endogene caves.^[2]^[3]

Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called caving, potholing, or spelunking.

^ "cave". Oxford English Dictionary (Online ed.). Oxford University Press. doi:10.1093/OED/8886318356. (Subscription or participating institution membership required.)
^ Moratto, Michael J. (2014). California Archaeology. Academic Press. p. 304. ISBN 9781483277356.
^ Lowe, J. John; Walker, Michael J. C. (2014). Reconstructing Quaternary Environments. Routledge. pp. 141–42. ISBN 9781317753711.

[1] "cave". Oxford English Dictionary (Online ed.). Oxford University Press. doi:10.1093/OED/8886318356. (Subscription or participating institution membership required.)

[2] Moratto, Michael J. (2014). California Archaeology. Academic Press. p. 304. ISBN 9781483277356.

[3] Lowe, J. John; Walker, Michael J. C. (2014). Reconstructing Quaternary Environments. Routledge. pp. 141–42. ISBN 9781317753711.

[1]

[2]

[3]