Caving is the recreational hobby of exploring caves. Speleology is the scientific study of caves and the cave environment.

The challenges of the hobby depend on the cave being visited, but often include the negotiation of pitches, squeezes, and water. Climbing or crawling is often necessary, and ropes are used extensively.

Caving is often undertaken for the enjoyment of the activity or for physical exercise, but original exploration, or physical or biological science is an important goal for many cavers. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate and enter them. In well-explored regions (such as most first-world countries), the most accessible caves have already been explored, and gaining access to new caves often requires digging or diving.

Caves have been explored out of necessity for thousands of years, but only in the last century or two has the activity developed into a sophisticated, athletic pastime. In recent decades caving has changed considerably due to the availability of modern protective wear and equipment. It has recently come to be known as an "extreme sport" by some (though not commonly considered as such by its practitioners, who may dislike the term for its perceived connotation of disregard for safety.)

Many of the skills of caving can also be used in the nature activities of mine exploration and urban exploration.
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Naming issues

Clay Perry — an American caver of the 1940s — wrote about a group of men and boys who explored and studied caves throughout New England. This group referred to themselves as spelunkers. This is regarded as the first use of the word in the Americas. Throughout the 1950s, spelunking was the general term used for exploring caves in US English. It was used freely, without any positive or negative connotations, although only rarely outside the US.

In the 1960s, the term "spelunking" began to convey the idea of inexperienced cavers, using unreliable light sources and cotton clothing. In 1985, Steve Knutson (editor of American Caving Accidents) made the following distinction:

"...Note that I use the term 'spelunker' to denote someone untrained and unknowledgeable in current exploration techniques, and 'caver' for those who are."

This sentiment is exemplified by bumper stickers and t-shirts displayed by many cavers: "Cavers rescue spelunkers".

Potholing refers to the act of exploring potholes, a word originating in the north of England for predominantly vertical caves. The term is often used as a synonym for caving, and outside the caving world there is a general impression that potholing is a more "extreme" version of caving.
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