South Downs

South Downs
The Seven Sisters, near Eastbourne, viewed from Seaford Head
Highest point
Peak	Butser Hill
Elevation	271 m (889 ft)
Coordinates	50°58′39.61″N 0°58′53.4″W / 50.9776694°N 0.981500°W / 50.9776694; -0.981500
Dimensions
Area	670 km2 (260 sq mi)
Naming
Etymology	Old English dūn, meaning 'hill'
Geography
Country	England
State/Province	Hampshire, East Sussex, West Sussex
Range coordinates	50°55′N 0°30′W / 50.92°N 0.5°W / 50.92; -0.5Coordinates: 50°55′N 0°30′W / 50.92°N 0.5°W / 50.92; -0.5
Parent range	Southern England Chalk Formation
Geology
Orogeny	Alpine orogeny
Age of rock	Cretaceous
Type of rock	chalk

The South Downs are a range of chalk hills that extends for about 260 square miles (670 km²) across the south-eastern coastal counties of England from the Itchen Valley of Hampshire in the west to Beachy Head, near Eastbourne, East Sussex, in the east. It is bounded on its northern side by a steep escarpment, from whose crest there are extensive views northwards across the Weald. The South Downs National Park forms a much larger area than the chalk range of the South Downs and includes large parts of the Weald.

The South Downs are characterised by rolling chalk downland with close-cropped turf and dry valleys, and are recognised as one of the most important chalk landscapes in England. The range is one of the four main areas of chalk downland in southern England.

The South Downs are relatively unpopulated compared to South East England as a whole, although in Sussex there has been large-scale urban encroachment onto the chalk downland by major seaside resorts, including most notably Brighton and Hove.

The South Downs have been inhabited since ancient times and at periods the area has supported a large population, particularly during Romano-British times. There is a rich heritage of historical features and archaeological remains, including defensive sites, burial mounds and field boundaries. Within the South Downs Environmentally Sensitive Area there are thirty-seven Sites of Special Scientific Interest, including large areas of chalk grassland.

The grazing of sheep on the thin, well-drained chalk soils of the Downs over many centuries and browsing by rabbits resulted in the fine, short, springy turf, known as old chalk grassland, that has come to epitomise the South Downs today. Until the middle of the 20th century, an agricultural system operated by downland farmers known as 'sheep-and-corn farming' underpinned this: the sheep (most famously the Southdown breed) of villagers would be systematically confined to certain corn fields to improve their fertility with their droppings and then they would be let out onto the downland to graze. However, starting in 1940 with government measures during World War II to increase domestic food production and continuing into the 1950s, much grassland was ploughed up for arable farming, fundamentally changing the landscape and ecology, with the loss of much biodiversity. As a result, while old chalk grassland accounted for 40-50% of the eastern Downs before the war, only 3-4% survives. This and development pressures from the surrounding population centres ultimately led to the decision to create the South Downs National Park, which came into full operation on 1 April 2011, to protect and restore the Downs.