Above the Downs: Documenting human history from the Neolithic to the Cold War

A recent survey project has analysed almost 10,000 aerial photographs as well as LiDAR imagery to explore archaeological features preserved within a large swathe of the South Downs National Park. From monuments to military remains, both well-known sites and new discoveries have been brought to light, as Carly Hilts reports.

Over thousands of years of history, the chalk grasslands of the South Downs have witnessed almost every aspect of the human condition, from burial rites and domestic life to agricultural, industrial, recreational, and military activities. These events have helped to shape its distinctive landscape, and while many leave enduring marks, other traces are more ephemeral, and not always visible to the naked eye. A recent aerial survey project, however, has illuminated a wealth of features spanning the Neolithic period to the Cold War, within a 192 square kilometre area of the South Downs National Park to the north of Brighton & Hove.

Overlooking the remains of a motte-and-bailey castle on Edburton Hill in the South Downs.

The survey, which was undertaken by Historic England’s Aerial Survey Team as part of the NHLF-supported Changing Chalk initiative (a four-year partnership led by the National Trust), involved a detailed study of over 9,500 aerial photographs from the Historic England Archives, taken by archaeologists, the RAF, and the Ordnance Survey between the 1920s and 2018. These were complemented by LiDAR images (aircraft-mounted laser scans that can be used to build 3D digital models of the ground below) from the Environment Agency and, together, these pictures have allowed researchers to explore traces of human activity spanning millennia.

Their findings have fed into a new interactive map that members of the public can use to explore the landscape, add their own data, report the current condition of earthworks, and share personal connections to a site. Detailed discussions of the project have also been published in a new Historic England research report (see ‘Further information’ on p.41 for more on this and the map), highlighting a diverse array of features, from monuments and earthworks to structures and routeways, as well as revealing buried remains visible only as soil- or cropmarks, and providing vital records of lost sites that have been ploughed out or built over since they were last photographed.

Some of the images show sites that are already well known and extensively explored by archaeologists – such as the Neolithic causewayed enclosures at Whitehawk and Offham (CA 58 and 88); the Iron Age hillfort at Devil’s Dyke; and the motte and bailey castle remains on Edburton Hill – but the survey has also uncovered exciting new discoveries. Previously, only one Neolithic long barrow had been identified within the entire project area (at Plumpton Plain), but now another candidate has been spotted on the north slope of Newmarket Hill, near Falmer. It survives as a low, ditch-flanked mound visible in both aerial photographs and LiDAR images; at its western end, a circular mound suggests that the site may have later gained a Bronze Age round barrow, with later prehistoric communities perhaps adopting and adapting a monument that they perceived as having ancestral connections.

Bronze Age barrows are the most common funerary monument associated with the South Downs, with 247 confirmed or potential examples documented within the project area alone. Particularly dense concentrations have been observed on the eastern and north-eastern edges of the Downs – and, just as they sometimes repurposed Neolithic burial sites, some in turn seem to have attracted clusters of early medieval barrows. Many of the mounds have been levelled by modern agriculture, their presence echoed only by cropmarks in aerial photographs, or as subtle changes in height that can be picked up by LiDAR scans.

Archaeological mapping within the area covered by the recent aerial survey. Image: Archaeological mapping © Historic England. Base map © Crown copyright and database right 2023

During the recent survey a large number of low, roughly circular mounds were spotted in this way.Some of these were isolated finds, but a possible barrow cemetery was also identified just to the south of Devil’s Dyke hillfort. This offers an invaluable opportunity to learn more about such monuments, the report’s authors note, as there has been little detailed study of the barrows in this area of the South Downs in recent years. Other earthworks within the same field have been linked to a ladies’ golf course that operated at Devil’s Dyke during the interwar years (aerial imagery reveals traces of a possible green and two bunkers to the south of the known location of its clubhouse) and to armoured vehicle and infantry exercises in the 1940s (more on the Downs’ wartime use later).

The earthworks of a possible Neolithic long barrow are captured in this photograph from the 1940s. A trackway goes over the top of the mound and it is abutted by an anti-glider trench to the south. Image: Historic England Archive (RAF Photography)

Field systems and farming

Another intriguing aspect of the many burial mounds examined during the survey is that some of them (for example, at Tennant Hill, Falmer Hill, Balmer Down, and Stanmer Down) seem to have influenced the layout of later Iron Age and Roman field systems, whose boundary lines appear to change course to deliberately incorporate, enclose, or avoid the monuments. These field systems are the most common type of archaeological feature recorded by the project, with extensive networks observed across the area of study. While their earthworks are often difficult to see on the ground, they are easily identifiable in LiDAR images, and it is hoped that further research will help to create a more accurate picture of local settlement patterns in later prehistory and the Roman period.

Moving into the medieval period, evidence of arable farming was very limited, the report authors write, represented only by distinctive strip lynchets on slopes, reflecting the difficulty of ploughing these steep, marginal spaces. Very little evidence, too, of ridge and furrow was seen during the survey; what there was, was seen in the Weald, and these traces were so straight and regular as to suggest that they are post-medieval in date. Instead, the main farming industry seen through much of the Downs’ history has been rearing livestock, particularly sheep. This activity is reflected in the presence of many man-made drinking pools called dewponds, as well as livestock enclosures of various sizes, and traces of tracks and holloways that would have been used by generations of humans and animals.

The sinuous lines of these pathways are difficult to date, but rather easier to pin down are the characteristically straight routes of Roman roads. Within the project area, researchers have identified part of what is thought to be the Greensand Way; sections of its path are visible as slight embankments and cuttings in the LiDAR images, which also pinpoint where it was crossed by the main Roman London-to-Brighton road. Excitingly, echoes of what may be a previously unknown branch road joining the route, with a junction west of Folly Wood, can also be seen in the form of very faint earthwork traces.

Western Brow, near Westmeston village, is home to a series of burial mounds; the larger barrows are thought to be Bronze Age in date, while the smaller ones  encircled by ring ditches are thought to be early medieval. 

Other routes observed during the survey represent a distinctive feature of the South Downs: droveways locally known as ‘bostalls’ (from the Old English beorg, ‘hill’, and stig/stigel, ‘rising path’), which are typically deeply worn and angled across a slope. Some have been surfaced and adopted as roads, some repurposed for military use – for example, Plumpton Bostall, which was concreted to allow tanks and artillery to access the Downs for military training in the 1940s – and some are still in use as bridleways and footpaths.

Work and play

As well as sheep farming, chalk extraction has also long been an important aspect of Downland life, with the material quarried for use in construction (mortar, limewash) and improving agricultural land over many centuries. The scars of this activity can still be seen in landscape, with numerous pits and quarries spotted within the survey area. Many of these features remain undated, but the largest area of pits and associated works operated at Offham, near Lewes, in 1809-1890. At its peak, the quarry extended over an area of c.700m by 300m, and was accompanied by four lime kilns; its creation also saw the removal of the eastern half of Offham Hill’s Neolithic causewayed enclosure.

LiDAR showing part of  the field system on Balmer Down. Images: © Historic England. Source Environment Agency

Flint mining boasts an even longer pedigree on the Downs, with significant Neolithic remains known from sites such as Blackpatch and Cissbury Ring in West Sussex (CA 389). While the project area did not yield such early evidence of this activity, some of the survey images did document an 18th- to early 19th-century flint mine on Wolstonbury Hill, where inhabitants of Hurstpierpoint workhouse laboured to serve the demand for gunflints. Their efforts were prolific; aerial photographs and LiDAR images both show the area to be peppered with small pits cutting through and extending beyond the site’s known late Bronze Age hilltop enclosure.

Trackways between Westmeston Bostall and Plumpton Bostall (‘bostall’ is a local word for a rising pathway). Images: © Historic England. Source Environment Agency

If agriculture and industry have been influential in shaping the destiny of the South Downs, however, the coming of the railways proved revolutionary, propelling rural Sussex into a new life as a popular Victorian holiday destination. While many of these visitors sought the seaside spectacle of places like Brighton, inland areas were also shaped by demands for recreation, some of whose echoes could be seen within the survey area. Chief among these was Devil’s Dyke, which became a 19th-century pleasure ground, with attractions filling the interior of the Iron Age hillfort. Contemporary postcards and writings testify to the varied delights on offer, among them a hotel, tea pavilions, and bandstands; swings, rifle-shooting, and fortune-tellers; a 7-ton replica naval gun; and even a zoo. There were also rides including a rollercoaster, a ‘bicycle railway’ where visitors could ride what was then an excitingly novel form of transport around a fixed circular rail, and an aerial ropeway carrying particularly daring passengers across the valley in a metal cage suspended between two pylons.

The fairground was served by a purpose-built railway – an ambitious undertaking navigating a 1 in 40 gradient – connected to the main Brighton-to-Portsmouth line. It opened in 1887, and a decade later was joined by a funicular; both were ultimately superseded by motor buses, but the remains of the railway’s track bed and the site of its station can still be seen in aerial photographs and LiDAR images. The funicular’s cutting and foundations also remain visible, though its track and station buildings are long gone. As for the fairground, today the hillfort’s interior has returned mostly to grass, although a circular platform 50m in diameter betrays the location of the bicycle railway, while keen-eyed visitors can also pick out the concrete footings of the towers and station for the aerial ropeway.

Military matters

Perhaps the most dramatic changes to the South Downs, however, were driven by military needs. Early echoes of this process come from the late 19th century, which saw the construction of rifle ranges (for example, at Whitehawk and near Thundersbarrow Hill), and the staging of large-scale exercises, but the mass-mobilisation of the First World War required infrastructure on an unprecedented scale. It must have come as a shock to the inhabitants of Shoreham-by-Sea, a small port town between Brighton and Worthing, for example, when thousands of troops suddenly poured out of its railway station in September 1914. They were to be accommodated in a new encampment and training site on Slonk Hill – initially in bell tents and then in (slightly) more comfortable huts. These were organised in blocks dedicated to individual battalions, and over the course of the war the site was home to more than 100,000 soldiers from across the UK and the Commonwealth (including my great-grandfather, Franklin Hilts of the Canadian Expeditionary Force). Although the camp was demolished soon after the Armistice, many earthworks, building footings, and the remains of training features such as practice trenches, assault courses, and rifle ranges survived long enough to be captured in RAF photographs during the 1940s. These images provide a ghostly plan of the once-bustling camp; traces that were destroyed by ploughing and urban growth soon after the end of the Second World War.

Devil’s Dyke, too, saw another dramatic change of use in 1918, becoming the Brighton Bomb Testing Station. On either side of the valley, rail/trolley tracks held a ropeway from which bombs could be dropped into the ravine, and these tracks can still be seen in aerial photographs and in LiDAR, running for c.150m as shallow ditches, as can a platform for a building or observation dugout. It is not known if any bombs were actually tested at the site, as it was only completed three days before the end of the war, but five circular hollows at the bottom of the valley could be craters hinting that the facility had seen at least some use.

Now abandoned and overgrown, Offham’s pits and kilns once represented the largest extraction site within the survey area.

During the Second World War, meanwhile, large areas of the Downs were requisitioned for military training, and later became a staging post for the D-Day invasions. With the Sussex coast deemed a likely landing point for any German invasion, defensive features were also of paramount importance. Many local hillforts, including at Devil’s Dyke and Ditchling Beacon, were pressed into reviving their ancient protective role, with historical photographs showing their earthworks augmented with barbed wire. Building platforms and the sites of anti-aircraft guns, weapons pits, and trenches can be seen in 1940s RAF photographs from across the survey area, while south of Saddlescombe a round cropmark still visible in photographs from the 1970s is not the outline of a lost prehistoric monument, but a turning circle built for armoured vehicles. The most heavily defended site in the central Downs, though, was at RAF Truleigh Hill, a radar station that operated from 1940 until 1958. The facility was demolished in 1965, but aerial photographs allow us to see it at its Second World War-era peak, and to trace how its buildings were repeatedly remodelled as it continued in use during the Cold War.

Although the First World War training camp at Shoreham-by-Sea was demolished shortly after the Armistice, its remains survived as earthworks until the 1940s, when this photograph was taken. Image: Historic England Archive (RAF Photography)

The lives of local civilians were also increasingly impacted by the growing military presence in the Downs. Roads were closed, large areas of the landscape were barred to public access for years, and farms were evacuated – and, in some places, requisitioned for target practice, as aerial photographs of ruins and shell craters attest. Urban communities, meanwhile, faced a different kind of threat, not only to their homes, but to their lives. Most of the built-up areas of Brighton, Hove, and Shoreham-by-Sea were excluded from the survey area, but aerial photographs of Lewes reflect civil defences that would have been replicated throughout Sussex’s towns. Lewes’ railway was targeted by the Luftwaffe on numerous occasions, and many houses were lost to German bombers; long after this threat had passed and the defences were removed once more, aerial photographs preserve the locations of air-raid shelters and water tanks for firefighting.

Even as military infrastructure receded in peacetime, the lasting effects of the conflict would make dramatic, permanent changes to the South Downs. With rationing continuing into the 1950s, large tracts of pasture were converted into arable fields to boost food production, and most of this land never returned to its previous use. It was a significant change for the local economy, but also for local archaeology, as swathes of chalkland were put to the plough for the first time. Thanks to aerial imagery, however, it is possible to recapture some of the fragile remains that were swept away by this transformation.

Looking along the northern scarp of the South Downs, from Ditchling Beacon, the highest point in East Sussex, whose summit is crowned by an Iron Age hillfort.

Further information
• To read the whole research report online for free, search for ‘Changing Chalk’ or 16/2023 at https://historicengland.org.uk/research/results/reports
• You can explore the features documented during the survey via an interactive map at https://experience.arcgis.com/experience/299ccde28277445e9d50e379998704b3. The project team would love for users to help enhance the stories that it tells by adding their own comments, memories, and old photographs to individual entries.
• For more information about the Changing Chalk partnership, see http://www.nationaltrust.org.uk/visit/sussex/the-changing-chalk-partnership

All images: © Historic England Archive, unless otherwise stated.