Often described as the "backbone of England", the Pennine Hills form a more-or-less continuous range stretching northwards from the Peak District in the northern Midlands, through the South Pennines, Yorkshire Dales and North Pennines up to the Tyne Gap, which separates the range from the Cheviot Hills. South of the Aire Gap is a western spur into east Lancashire, comprising the Rossendale Fells, West Pennine Moors and the Bowland Fells in North Lancashire. The Howgill Fells in Cumbria are sometimes considered to be a Pennine spur to the west of the range. The Pennines are an important water catchment area with numerous reservoirs in the head streams of the river valleys.
The region is widely considered to be one of the most scenic areas of the United Kingdom. The North Pennines and Nidderdale are designated Areas of Outstanding Natural Beauty (AONB) within the range, as are Bowland and Pendle Hill. Parts of the Pennines are incorporated into the Peak District National Park and the Yorkshire Dales National Park. Britain's oldest long-distance footpath, the Pennine Way, runs along most of the Pennine Chain and is 268 miles (429 km) long.
The Cheviot Hills, separated by the Tyne Gap and the Whin Sill, along which run the A69 and Hadrian's Wall, are not part of the Pennines but, perhaps because the Pennine Way crosses them, they are often treated as such. As a result, the northern end of the Pennines may be considered to be either at the Tyne Gap or the Cheviot Hills across the Anglo-Scottish border. Conversely the southern end of the Pennines is commonly said to be in the High Peak of Derbyshire at Edale, the start of the Pennine Way. However, hills continue towards southern Derbyshire, northern Staffordshire, eastern Cheshire, and western Nottinghamshire.
Various etymologies have been proposed treating "Pennine" as though it were a native Brittonic/Modern Welsh name related to pen- ("head") . In fact, it did not become a common name until the 18th century and almost certainly derives from modern comparisons with the Apennine Mountains, which run down the middle of Italy in a similar fashion.