|Elevation||271 m (889 ft)|
|Coordinates||50°58′40″N0°58′49″W / 50.97778°N 0.98028°W|
|Area||670 km2 (260 sq mi)|
|Etymology||Old English dūn, meaning 'hill'|
|Country||England (United Kingdom)|
|Region||Hampshire, East Sussex, West Sussex|
|Range coordinates||50°54′N0°30′W / 50.9°N 0.5°W Coordinates: 50°54′N0°30′W / 50.9°N 0.5°W|
|Parent range||Southern England Chalk Formation|
|Age of rock||Cretaceous|
|Type of rock||Chalk|
The South Downs are a range of chalk hills in the south-eastern coastal counties of England that extends for about 260 sq mi (670 km2)  across the south-eastern coastal counties of England from the Itchen valley of Hampshire in the west to Beachy Head, in the Eastbourne Downland Estate, East Sussex, in the east. The Downs are bounded on the 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 less populated compared to South East England as a whole, although 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 the Second World War to increase domestic food production – which continued 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.
The South Downs have also been designated as a National Character Area (NCA 125) by Natural England. It is bordered by the Hampshire Downs, the Wealden Greensand, the Low Weald and the Pevensey Levels to the north and the South Hampshire Lowlands and South Coast Plain to the south. 
The downland is a highly popular recreational destination, particularly for walkers, horseriders and mountain bikers. A long distance footpath and bridleway, the South Downs Way, follows the entire length of the chalk ridge from Winchester to Eastbourne, complemented by many interconnecting public footpaths and bridleways.
The term 'downs' is from Old English dūn, meaning 'hill'. The word acquired the sense of 'elevated rolling grassland' around the 14th century.  These hills are prefixed 'south' to distinguish them from another chalk escarpment, the North Downs, which runs roughly parallel to them about 30 mi (48 km) away on the northern edge of the Weald.
The South Downs are formed from a thick band of chalk which was deposited during the Cretaceous Period between 100 and 66 million years ago within a shallow sea which extended across much of northwest Europe. The rock is composed of the microscopic skeletons of plankton which lived in the sea, hence its colour. The chalk has many fossils, and bands of flint occur throughout the formation.  The Chalk is divided into the Lower, Middle and Upper Chalk, a thin band of cream-coloured nodular chalk known as the Melbourn Rock marking the boundary between the Lower and Middle units.
The strata of southeast England, including the Chalk, were gently folded during a phase of the Alpine Orogeny to produce the Weald-Artois Anticline, a dome-like structure with a long east-west axis. Erosion has removed the central part of the dome, leaving the north-facing escarpment of the South Downs along its southern margin with the south-facing chalk escarpment of the North Downs as its counterpart on the northern side, as shown on the diagram. Between these two escarpments the anticline has been subject to differential erosion so that geologically distinct areas of hills and vales lie in roughly concentric circles towards the centre; these comprise the Greensand Ridge, most prominent on the north side of the Weald, where it includes Leith Hill, the highest hill in south-east England, the low-lying clay vales of the Low Weald, formed of less resistant Weald Clay, and finally the more highly resistant sandstones of the High Weald at the centre of the anticline, whose elevated forest ridge includes most notably Ashdown Forest. 
The chalk, being porous, allows water to soak through; as a result there are many winterbournes along the northern edge.
The South Downs are a long chalk escarpment that stretches for over 110 km (68 mi), rising from the valley of the River Itchen near Winchester, Hampshire, in the west to Beachy Head near Eastbourne, East Sussex, in the east.  Behind the steep north-facing scarp slope, the gently inclined dip slope of undulating chalk downland extends for a distance of up to 7 mi (11 km) southwards. Viewed from high points further north in the High Weald and on the North Downs, the scarp of the South Downs presents itself as a steep wall that bounds the horizon, with its grassland heights punctuated with clumps of trees (such as Chanctonbury Ring).
In the west, the chalk ridge of the South Downs merges with the North Downs to form the Hampshire Downs. In the east, the escarpment terminates at the English Channel coast between Seaford and Eastbourne, where it produces the spectacular white cliffs of Seaford Head, the cross-section of dry valleys known as the Seven Sisters and Beachy Head, the highest chalk sea cliff in Britain at 162 m (531 ft) above sea level.
The South Downs may be said to have three main component parts: the East Hampshire Downs, the Western Downs and the Eastern Downs, together with the river valleys that cut across them and the land immediately below them, the scarpfoot.  The Western and Eastern Downs are often collectively referred to as the Sussex Downs. The Western Downs, lying west of the River Arun, are much more wooded, particularly on the scarp face, than the Eastern Downs. The bare Eastern Downs – the only part of the chalk escarpment to which, until the late 19th century, the term "South Downs" was usually applied – have come to epitomise, in literature and art, the South Downs as a whole and which have been the subject matter of such celebrated writers and artists as Rudyard Kipling (the "blunt, bow-headed, whale-backed downs") and Eric Ravilious. 
Four river valleys cut through the South Downs, namely those of the rivers Arun, Adur, Ouse and Cuckmere, providing a contrasting landscape. Chalk aquifers and to a lesser extent winterbourne streams supply much of the water required by the surrounding settlements. Dew ponds, artificial ponds for watering livestock, are a characteristic feature on the downland.
The highest point on the South Downs is Butser Hill, whose summit is 271 m (889 ft) above sea level. The plateau-like top of this irregularly shaped hill, which lies just south of Petersfield, Hampshire, was in regular use through prehistory. It has been designated as a national nature reserve.
Within the boundary of the South Downs National Park, which includes parts of the western Weald to the north of the South Downs, the highest point is Blackdown, West Sussex, which rises to 280 m (919 ft) above sea level. However, Blackdown geologically is not part of the South Downs but instead forms part of the Greensand Ridge on the Weald's western margins.
A list of those points on the South Downs above 700 ft (210 m), going from west to east, is given below.
|Name of hill||Nearest settlement||Height||Notes|
|Butser Hill||Petersfield||270 m (886 ft)||Highest point in the South Downs proper.|
|West Harting Down||South Harting||229 m (751 ft)|
|Beacon Hill||South Harting||242 m (793 ft)|
|Linch Down||Bepton||248 m (814 ft)|
|Littleton Down||East Lavington||255 m (836 ft)||The summit, Crown Teglease, is the highest point on the Sussex Downs.|
|Glatting Beacon||Sutton||245 m (803 ft)|
|Chanctonbury Hill||Washington||238 m (782 ft)||Site of Chanctonbury Ring hill fort|
|Truleigh Hill||Upper Beeding||216 m (708 ft)|
|Ditchling Beacon||Ditchling||248 m (814 ft)|
|Firle Beacon||Firle||217 m (713 ft)|
Archaeological evidence has revealed that the Downs have been inhabited and utilised for thousands of years. Neolithic flint mines such as Cissbury, burial mounds such as the Devil's Jumps and Devil's Humps, and hill forts like Chanctonbury Ring are strong features in the landscape.  
It has been estimated that the tree cover of the Downs was cleared over 3000 years ago, and the present closely grazed turf is the result of continual grazing by sheep.
Proposals to create a national park for the South Downs date back to the 1940s. However, it was not until 1999 that the idea received firm government support. After a public enquiry that took place between 2003 and 2009, the government announced its decision to make the South Downs a national park on 31 March 2009. The South Downs National Park finally came into operation on 1 April 2011. Within its boundary are included not only the South Downs proper but also part of the western Weald, a geologically and ecologically quite different district.
The South Downs National Park has replaced two Areas of Outstanding Natural Beauty (AONB)s: East Hampshire AONB and Sussex Downs AONB. During the enquiry process a number of boundary questions were considered, so that the National Park contains areas not in the former AONBs, and vice versa.
The South Downs contain a number of national nature reserves (NNRs). 
The NNRs on the Sussex Downs comprise Kingley Vale, near Chichester, said by Natural England to contain one of the finest yew forests in Europe, including a grove of ancient trees which are among the oldest living things in Britain (the reserve is also one of the most important archaeological sites in southern England, with 14 scheduled monuments); Castle Hill, between Brighton and Lewes, an important example of ancient, traditionally managed grassland; Lewes Downs (Mount Caburn), a traditionally managed chalk downland (and also an important archaeological site); and Lullington Heath, on the northern fringe of Friston Forest north-west of Eastbourne, one of the largest areas of chalk heath in Britain.
The NNRs on the East Hampshire Downs comprise Butser Hill, near Petersfield, a large area of chalk grassland on the highest point in the South Downs (a large area is also designated as a scheduled monument reflecting its historical significance, particularly in the Bronze and Iron Ages); Old Winchester Hill, a lowland grassland on the west and south facing scarp slopes of the Meon valley; and Beacon Hill, a high quality chalk grassland 5 km west of Old Winchester Hill.
In 1923 the Society of Sussex Downsmen (now the South Downs Society) was formed with the aim of protecting the area's unique landscape. 
The South Downs are a popular area for ramblers with a network of over 2,000 mi (3,200 km) of well-managed, well-signed and easily accessible trails. The principal bridleway, and longest of them, is the South Downs Way.  The Monarch's Way, having originated at Worcester, crosses the South Downs and ends at Shoreham-by-Sea. 
Sports undertaken on the Downs include paragliding, mountain-biking, horse riding and walking.  The popular Beachy Head Marathon (formerly Seven Sisters Marathon), a hilly cross-country marathon, takes place each autumn on the eastern Downs, starting and finishing in Eastbourne. The South Downs Trail Marathon starts in the village of Slindon (near Arundel) and ends at the Queen Elizabeth Country Park (to the south of Petersfield.)
Longer events that take in the South Downs Way include a 100-mile running 'ultramarathon' and mountain biking 75 mile night time race from Beachy Head to Queen Elizabeth Country Park.
Three of the landmarks on the Downs are the Long Man of Wilmington and the Litlington White Horse being chalk carved hill figures, and Clayton Windmills. There is also a war memorial, The Chattri, dedicated to Indian soldiers who died in the Brighton area, having been brought there for treatment after being injured fighting on the Western Front in the First World War.
Rudyard Kipling who lived at Rottingdean described the South Downs as "Our blunt, bow-headed whale-backed Downs".  Writing in 1920 in his poem The South Country, poet Hilaire Belloc describes the South Downs as "the great hills of the South Country".  In On The South Coast, poet Algernon Charles Swinburne describes the South Downs as "the green smooth-swelling unending downs". 
The naturalist-writer William Henry Hudson wrote that "during the whole fifty-three mile length from Beachy Head to Harting the ground never rises above a height of 850 feet, but we feel on top of the world". 
Poet Francis William Bourdillon also wrote a poem "On the South Downs".  The South Downs have been home to several writers, including Jane Austen who lived at Chawton on the edge of the Downs in Hampshire. The Bloomsbury Group often visited Monk's House in Rodmell, the home of Virginia Woolf in the Ouse valley. Alfred, Lord Tennyson, had a second home at Aldworth, on Blackdown; geologically part of the Weald, Blackdown lies north of the South Downs but is included in the South Downs National Park.
In the introduction to Arthur Conan Doyle's short story collection His Last Bow, Dr. Watson states that Sherlock Holmes has retired to a small farm upon the Downs near Eastbourne. In the story "His Last Bow" itself, Holmes states that he "lives and keeps bees upon the South Downs". Furthermore, the short story "The Lion's Mane" is about a case that Holmes solves whilst living there.
The author Graham Greene's first published novel, The Man Within (1929), is set largely on and around the South Downs. The book's principal character, Andrews, travels by foot across the Downs to reach Lewes and attend the Assizes. Greene provides a detailed description of both the landscape and its 'feel'.
The author H. G. Wells published a book called The Invisible Man in 1898, and in it says "He fled to South Down".
East Sussex is a ceremonial and non-metropolitan county in South East England on the English Channel coast. It is bordered by Kent to the north and east, West Sussex to the west, and Surrey to the north-west. The largest settlement in East Sussex is the city of Brighton and Hove.
Downland, chalkland, chalk downs or just downs are areas of open chalk hills, such as the North Downs. This term is used to describe the characteristic landscape in southern England where chalk is exposed at the surface. The name "downs" is derived from the Old English word dun, meaning "hill".
The South Downs Way is a long distance footpath and bridleway running along the South Downs in southern England. It is one of 16 National Trails in England and Wales. The trail runs for 160 km (100 mi) from Winchester in Hampshire to Eastbourne in East Sussex, with about 4,150 m (13,620 ft) of ascent and descent.
The North Downs are a ridge of chalk hills in south east England that stretch from Farnham in Surrey to the White Cliffs of Dover in Kent. Much of the North Downs comprises two Areas of Outstanding Natural Beauty (AONBs): the Surrey Hills and the Kent Downs. The North Downs Way National Trail runs along the North Downs from Farnham to Dover.
The South Downs National Park is England's newest national park, designated on 31 March 2010. The park, covering an area of 1,627 square kilometres (628 sq mi) in southern England, stretches for 140 kilometres (87 mi) from Winchester in the west to Eastbourne in the east through the counties of Hampshire, West Sussex and East Sussex. The national park covers the chalk hills of the South Downs and a substantial part of a separate physiographic region, the western Weald, with its heavily wooded sandstone and clay hills and vales. The South Downs Way spans the entire length of the park and is the only National Trail that lies wholly within a national park.
Hamsey is a civil parish in the Lewes District of East Sussex, England. The parish covers a large area and consists of the villages of Hamsey, Offham and Cooksbridge. The main centres of population in the parish are now Offham and Cooksbridge. Around the main settlements are enlarged fields, isolated old cottages and farms. The winding and undulating parish lanes between banks, old hedge rows, trees, flowery verges and ditches are rightly popular with cyclists and give good views of the Downs.
Newtimber is a small village and civil parish in the Mid Sussex District of West Sussex, England. It is located north-west of Brighton. The parish also includes the hamlet of Saddlescombe. The parish lies almost wholly with the South Downs National Park, with the exception of a small section of the parish north of the B2117 road. The planning authority for Newtimber is therefore the South Downs National Park Authority (SDNPA), the statutory planning authority for the National Park area. The downland scarp, which includes Newtimber Hill, Newtimber Holt, Saddlescombe chalk quarry and Summer Down, is mostly part of the Beeding Hill to Newtimber Hill, designated Site of Special Scientific Interest.
Beacon Hill, Warnford is a 46.4-hectare (115-acre) biological Site of Special Scientific Interest west of Warnford in Hampshire. It is a Nature Conservation Review site, and an area of 40.1 hectares is a national nature reserve. There is a round barrow cemetery dating to the Late Neolithic or Bronze Age on the hill, and this is a scheduled monument.
Ditchling Beacon is the highest point in East Sussex, England, with an elevation of 248 m (814 ft). It is south of Ditchling and to the north-east of Brighton. It is a large chalk hill with a particularly steep northern face, covered with open grassland and sheep-grazing areas. It is the third-highest point on the South Downs, behind Butser Hill and Crown Tegleaze.
The Greensand Ridge, also known as the Wealden Greensand is an extensive, prominent, often wooded, mixed greensand/sandstone escarpment in south-east England. Forming part of the Weald, a former dense forest in Sussex, Surrey and Kent, it runs to and from the East Sussex coast, wrapping around the High Weald and Low Weald. It reaches its highest elevation, 294 metres (965 ft), at Leith Hill in Surrey—the second highest point in south-east England, while another hill in its range, Blackdown, is the highest point in Sussex at 280 metres (919 ft). The eastern end of the ridge forms the northern boundary of Romney Marsh.
East Hampshire Area of Outstanding Natural Beauty (AONB) in England was designated in 1962. The designation was revoked in March 2010, together with the neighbouring Sussex Downs AONB, upon the establishment of the South Downs National Park. The southern part of the area is mainly rolling chalk downland used for farming that is a westward extension of the Sussex Downs. The north and east includes steep wooded hills and heathland.
Sussex is a historic county and cultural region in the south of England corresponding roughly in area to the ancient Kingdom of Sussex. It is bounded on the north by Surrey, north-east by Kent, south by the English Channel, and west by Hampshire, and is divided for local government into West Sussex and East Sussex and the city of Brighton and Hove. The city of Brighton & Hove was created a unitary authority in 1997, and was granted City status in 2000. Until then Chichester had been Sussex's only city. By convention, Chichester is Sussex's capital city and Lewes is Sussex's county town.
Clayton to Offham Escarpment is a 422.5-hectare (1,044-acre) linear biological Site of Special Scientific Interest (SSSI) which runs from Clayton in West Sussex to Lewes in East Sussex. Its ownership and management is divided between over fifteen landowners and farmers. Parts of Ditchling's Downs, e.g. TQ 323 133, and the scarp between Blackcap and Mount Harry, e.g. TQ 378 124, are owned by the National Trust. What remains of Ditchling Tenantry Down common at Ditchling Beacon is leased to the Sussex Wildlife Trust.
The western Weald is an area of undulating countryside in Hampshire and West Sussex containing a mixture of woodland and heathland areas.
Blackcap is a hill and nature reserve in East Sussex, England. It is on a peak of the South Downs, just south east of Plumpton and west of Lewes. The flatter landscape is made up of open ground with chalk paths, surrounded by thickets. The steeper ground leading up to the ridge is low-density woodland. The top is more open, with patches of pine woodland and gorse bushes.
The Hampshire Downs form a large area of downland in central southern England, mainly in the county of Hampshire but with parts in Berkshire and Wiltshire. They are part of a belt of chalk downland that extends from the South Downs in the southeast, north to the Berkshire and Marlborough Downs, and west to the Dorset Downs.
The Upper Greensand Formation is a Cretaceous formation of Albian to Cenomanian in age, found within the Wessex Basin and parts of the Weald Basin in southern England. It overlies the Gault Clay and underlies the Chalk Group. It varies in thickness from zero to 75 m. It is predominantly a glauconitic fine-grained sandstone, locally becoming silty. Fragmentary dinosaur remains, such as those assigned to Iuticosaurus, have been recovered from this formation. It has been quarried as a building stone from Roman times, and used in London and the area of its outcrop from Devon to East Sussex.
The Eastbourne Downland Estate is an area of downland at the easternmost end of the South Downs National Park in East Sussex, England. It was bought by the public, following threats to the beauty spots of Beachy Head and the surrounding farmland, which led to a public campaign and Act of Parliament in 1926. It is currently owned and managed, on behalf of the public, by Eastbourne Borough Council.
The Worthing Downland Estate, Worthing Downs or Worthing Downland, is an area of land in the South Downs National Park in West Sussex, England, close to the town of Worthing. It was bought by the public, following threats to the beauty spot of Cissbury Ring and the surrounding farmland, which led to a public campaign purchases in the 1930s. It is currently owned and managed, on behalf of the public, by Worthing Borough Council.
The geology of the South Downs National Park in South East England comprises a gently folded succession of sedimentary rocks from the Cretaceous and early Palaeogene periods overlain in places by a range of superficial deposits from the last 2.6 million years. Whereas the South Downs are formed from the Late Cretaceous age chalk, the South Downs National Park extends into the Weald to the north of the range and thereby includes older rock strata dating from the Early Cretaceous including sandstones and mudstones. The youngest solid rocks are found on the southern fringes of the National Park in the eastern extension of the Hampshire Basin and include sand, silt and clay deposited during the Palaeocene and Eocene epochs.