Spelunking

Caving — also traditionally known as spelunking in the United States and Canada and potholing in the United Kingdom and Ireland — is the recreational pastime of exploring wild (generally non-commercial) cave systems. In contrast, speleology is the scientific study of caves and the cave environment.

The challenges involved in caving vary according to the cave being visited, but – in addition to the total absence of light beyond the entrance – often include the negotiation of pitches, squeezes, and water hazards.Cave diving is a distinct, and more hazardous, sub-speciality undertaken by a small minority of technically proficient cavers. In an area of overlap between recreational pursuit and scientific study, the most devoted and serious-minded cavers become accomplished at the surveying and mapping of caves and the formal (though usually private) publication of their efforts.

Sometimes categorized as an "extreme sport", it is not commonly considered as such by long-time enthusiasts, who may dislike the term for its connotation of disregard for safety.

Many caving skills overlap with those involved in canyoning, mine and urban exploration.

Caving is often undertaken for the enjoyment of the outdoor activity or for physical exercise, as well as original exploration, similar to mountaineering or diving. Physical or biological science is also an important goal for some cavers, while others are engaged in cave photography. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate, enter and survey them. In well-explored regions (such as most developed nations), the most accessible caves have already been explored, and gaining access to new caves often requires cave digging or cave diving.

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Wikipedia