In the British Isles, the terms hillwalking or fellwalking are commonly used to describe the recreational outdoor activity of walking on hills and mountains, often with the intention of visiting their summits. This can include activities which might be referred to as hiking, backpacking or mountaineering elsewhere, covering terrain which can include mountains, high moorland, remote passes and coastal walks.

Fellwalking is specifically used to refer to hill or mountain walks in the Lake District, Lancashire, especially the Forest of Bowland and the Yorkshire Dales in Northern England as fell is the preferred term for both features in those parts of England.

Britain offers a wide variety of ascents, from gentle rolling lowland hills to some very exposed routes in the moorlands and mountains. The term climbing is used for the activity of tackling the more technically difficult ways of getting up hills involving rock climbing while "hillwalking" refers to the easier routes.

Some summits require climbing skills, and many hillwalkers will become proficient in scrambling. In Britain, the term "mountaineering" tends to be reserved for expeditions abroad to ranges such as the Alps, or for serious domestic hillwalking, typically in winter, with additional equipment such as ice axe and crampons, or for routes requiring rock climbing skills such as the traverse of the Cuillin ridge. The British Mountaineering Council provides more information on this topic.

Chris Townsend is a passionate hillwalker and author of 15 books.

Townsend was the first person to climb all of the Munros and Tops in a continuous walk involving 1700 miles (2700 km) and 575,000 feet (170,000 m) of ascent over all 517 of the 3000 ft (914 m) Scottish summits listed in Munro's Tables. He was also the first person to walk the length of the Canadian Rockies, a distance of 1600 miles (2500 km). Chris Townsend has also hiked the 2600 mile (4200 km) Pacific Crest Trail, the 3100 mile (5000 km) Continental Divide Trail, Land's End to John o' Groats in the UK (1250 miles, 2000 km), south-north through the Scandinavian mountains (1300 miles, 2100 km), 1000 miles (1600 km) south-north through the Yukon Territory and the 800 mile (1300 km) Arizona Trail.