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 platform cairn and field system between The Plains and Wine
Cove survive well. Apart from the insertion of the modern boundary posts on
one side, the cairn appears undisturbed and has not been excavated. The field
system shows clearly its pattern and relationship to the local landforms,
complementing the extensive and broadly contemporary field system survivals to
each side along the north of St Martin's. The prolonged use of these field
systems and their eventual large scale abandonment, with limited 19th century
re-occupation evident within this scheduling as well as from early maps,
provides a good example of the major reorganisation of land use and the
far-reaching environmental changes that have followed from the gradual and
ongoing submergence of Scilly's land mass.
Details
The monument includes a prehistoric platform cairn and a prehistoric to early
post-medieval field system between The Plains and Wine Cove, on the ridge top
and northern slope of western St Martin's in the Isles of Scilly.
The scheduling also includes an area of the northern slope called Frenchmen's
Graves, considered to be a burial ground of early shipwreck victims. This
scheduling is divided into two separate areas.
The platform cairn survives on flattish ground on the island's spine, 175m ESE
of Plains House. It is visible as a low rounded mound, 11.5m east-west by 11m
north-south, rising 0.5m to a flattened upper platform 5.5m in diameter and
crossed on its ESE side by a modern field boundary.
Beyond this cairn, the northern coastal slope and crest of the island contains
extensive remains of early field systems whose known extent ranges from the
slope below The Plains on the WNW to the slope behind Wine Cove on the ESE.
The field system is visible both as low vegetation-covered banks, roughly
2m-3m wide and 0.2m-0.5m high, and as low rubble ridges crossing the footpaths
in this area. These reveal an overall rectilinear field pattern, with a series
of straight north east-south west banks running directly downslope to the
present cliff edge, subdividing the slope at intervals and joining a bank
running north west-south east along the midslope contour. A second bank runs
north west-south east along the slope crest, visible extending WNW from the
prominent Barnacle Rock on the area's local summit and passing through the
present scrub in the north of the adjacent modern field.
Exposures of bank rubble in footpaths indicate another boundary running for
several metres north east from the distinctive outcrop of Barnacle Rock,
meeting a third north west-south east boundary on the upper slope. To the east
of Barnacle Rock, the path immediately outside the modern limit of enclosure
is crossed by a series of north east-south west rubble ridges.
The overall field system visible within this scheduling includes elements from
successive phases of land use from the prehistoric to the early post-medieval.
The field system is regarded as a continuation of the extensive areas of
surviving prehistoric field system of similar character on the north of
St Martin's around Top Rock Hill to the north west and along much of the
eastern half of the island's northern flanks east of Turfy Hill. The remains
in this scheduling are defined visibly from those areas by deep medieval and
later deposits of blown sand and by dense surface vegetation, both of which
obscure surface traces of the field system on the intervening land. The
discovery beyond this scheduling of some early medieval artefacts at the base
of the blown sand layer south of Top Rock Hill indicate continued activity
into that period. In the mid-18th century the antiquary William Borlase noted
the traces of field boundaries on the north of the island as being long-
abandoned due to inundation by sand. The 1889 Ordnance Survey map shows a
small row of fields east of Barnacle Rock and extending a little north of the
present limit of enclosure; the rubble ridges crossing the modern path in
this sector are considered to derive from these 19th century plots and form
the final episode of land use forming the overall field system in this
scheduling.
On the lower slope in the north west of this scheduling is an ill-defined area
known as `Frenchmen's Graves', now obscured by scrub. Nineteenth century
Ordnance Survey maps show the location as a sub-circular area roughly 48m in
diameter, depicted as clear of the rough vegetation that covered the
neighbouring ground. Although reputedly a cemetery of shipwreck victims buried
by the coast close to where they were washed ashore as was the local custom
until the mid-19th century, the name and date of the wreck is not known.
The modern post-and-wire fence is excluded from the scheduling but the ground
beneath is included.
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.
