Prehistoric field system on Gweal Hill, Bryher

Reasons for Designation

The Isles of Scilly, the westernmost of the granite masses of south west England, contain a remarkable abundance and variety of archaeological remains from over 4000 years of human activity. The remote physical setting of the islands, over 40km beyond the mainland in the approaches to the English Channel, has lent a distinctive character to those remains, producing many unusual features important for our broader understanding of the social development of early communities. Throughout the human occupation there has been a gradual submergence of the islands' land area, providing a stimulus to change in the environment and its exploitation. This process has produced evidence for responses to such change against an independent time-scale, promoting integrated studies of archaeological, environmental and linguistic aspects of the islands' settlement. The islands' archaeological remains demonstrate clearly the gradually expanding size and range of contacts of their communities. By the post- medieval period (from AD 1540), the islands occupied a nationally strategic location, resulting in an important concentration of defensive works reflecting the development of fortification methods and technology from the mid 16th to the 20th centuries. An important and unusual range of post- medieval monuments also reflects the islands' position as a formidable hazard for the nation's shipping in the western approaches. The exceptional preservation of the archaeological remains on the islands has long been recognised, producing an unusually full and detailed body of documentation, including several recent surveys. Regular field systems are one of several methods of field layout known to have been employed in the Isles of Scilly from the Bronze Age to the Roman period (c.2000 BC - AD 400); closer dating within that period may be provided by the visible relationships of the field boundaries to other classes of monument with a shorter known time-span of use, or by their relationship with an earlier recorded sea level. They comprise a collection of field plots defined by boundaries laid out in a consistent manner, along two dominant axes at approximate right angles to each other. This results in rectilinear fields which may vary in their size and length:width ratio both within and between individual field systems. The fields are bounded by rubble walls or banks, often incorporating edge- or end- set slabs called orthostats. Within its total area, a regular field system may be subdivided into blocks differing in the orientations of their dominant axes. Regular field systems may be associated with broadly contemporary settlement sites such as stone hut circles. Some regular field systems on the Isles of Scilly contain a distinctive association, rarely encountered elsewhere, whereby certain of their field boundaries directly incorporate or link cairns, entrance graves and cists in some groups of prehistoric funerary monuments. Although no precise figure is available, regular field systems form one of the three principal forms of prehistoric field system, along with irregular field systems and some groups of prehistoric linear boundaries, which survive in over 70 areas of the Isles of Scilly. They provide significant insights into the physical and social organisation of past landscapes and they provide evidence for the wider contemporary context within which other nationally important monuments were constructed.

The prehistoric field system on Gweal Hill survives reasonably well, clearly displaying the character of the prehistoric land division and the strong influences upon it of the natural topography. Despite truncation of its lower edges by rising sea levels, the field system contains a sufficient range of elements to determine its nature and extent. The strong negative lynchet on the field system's upper boundary and its relationship with the broadly contemporary funerary cairns on the summit and northern slope of the hill demonstrates the wider manner in which farming and ritual activities were organised among the prehistoric communities which created this monument.

Details

The monument includes a prehistoric field system extending around the western and southern flanks of Gweal Hill on the west coast of Bryher, in the north west of the Isles of Scilly. The field system is defined by turf-covered rubble banks, up to 2m wide and 0.25m high, with a single row of closely spaced slabs, mostly edge-set, projecting along the midline of the banks. The slabs are generally 0.5m-1m apart and 0.4m-0.5m high, but rising to 0.7m high in some examples. Where the banks run along the slope they appear as marked steps, called lynchets, in the slope profile, caused by soil movement on the gradient against the banks' uphill sides and away from their downhill sides, a process accelerated by early cultivation. In the south and south east of the monument, the walls of two relatively recent but abandoned field plots overlie the prehistoric field walling, whose distinctively spaced large slabs remain visible along the base of the later walls which otherwise employ mostly smaller slabs. The field system's boundaries create a single line of plots along the west and south flanks of the hill; the sides of the plots are defined by at least six banks, 20m-75m apart, which run directly downslope to be truncated by the present coastline at their lower ends. The plot sides tend to be almost parallel, orientated WSW-ENE on the west flank and SSE-NNW on the south flank; the north west - south east alignment of the monument's easternmost boundary reflects the change in underlying slope as the field system reaches the east flank of the hill. The upper ends of the plots are defined by a lynchetted bank running along the midslope crossing the upper ends of the side walls generally 35m-50m behind the present coastline. On the western flank, where its form is least affected by dense scrub and by later walling built onto it, the lynchetting of this upper bank includes a particularly marked drop, 0.6m high, on its downslope side; this is called a negative lynchet and emphasises the considerable soil movement arising from the prehistoric cultivation in the plot below, contrasting with the far slighter natural soil creep against the uphill side from the unenclosed, uncultivated, summit area of the hill. The course of the lynchetted upper bank is strongly influenced by the location of natural bedrock outcrops along the midslope, the bank running in almost straight lengths directly linking one outcrop with the next and producing an overall zig-zagging course rather than an even line along the contour. This influence of outcrops on the layout of the upper bank is such that at its northern end, the bank extends for c.15m beyond its junction with the side wall of the northernmost plot to terminate on a large outcrop. Beyond this monument, the summit of Gweal Hill contains a group of three broadly contemporary funerary cairns from 30m east of the upper field bank on the western flank. Another smaller cairn is located at the foot of the northern slope of Gweal Hill, 110m north east of the field system's northern end. These four cairns are the subjects of separate schedulings.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.

Legacy

The contents of this record have been generated from a legacy data system.

Legacy System number:

15458

Legacy System:

RSM

Sources

Other
Title: 1:2500 Ordnance Survey Map; SV 8714 Source Date: 1980 Author: Publisher: Surveyor:
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7385, (1988)

End of official list entry

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