Caving, also known as spelunking and potholing, is the recreational pastime of exploring wild cave systems. It is an adventurous activity that involves exploring underground caves and caverns, and it can test you both physically and mentally. Caving can involve significant aspects of canyoning, climbing, and abseiling within an underground setting. Depending on where you go, caving can take you into different environments, from standing upright and walking around big open caverns to crawling through dark and incredibly narrow passages.

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.

Caving has also been described as an "individualists team sport" by some, as cavers can often make a trip without direct physical assistance from others but will generally go in a group for companionship or to provide emergency help if needed. Some, however, consider the assistance cavers give each other as a typical team sport activity.

The terms caving, spelunking, and potholing are often used interchangeably, but there is a key difference between these land formations: caves consist mostly of horizontal passages, while potholes are vertical. Although caving can potentially be dangerous, accidents or injury are rare. Despite this, it is not recommended to go alone, unless you are a competent caver. Even if you’re an experienced caver, never go alone and follow a guide if you’re exploring unknown territory.

In terms of equipment, cavers typically use ropes, helmets, and lights, and they often wear specialized clothing and footwear. Knots commonly used in caving are the figure-of-eight- (or figure-of-nine-) loop, bowline, and others. The British Caving Association is the governing body for underground exploration in the UK, and it provides advice on training, safety, and access to caves.