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Prehistoric cairn group and field systems on Great Arthur, St Martin's

A Scheduled Monument in St. Martin's, Isles of Scilly

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Latitude: 49.9435 / 49°56'36"N

Longitude: -6.264 / 6°15'50"W

OS Eastings: 94188.731265

OS Northings: 13531.629069

OS Grid: SV941135

Mapcode National: GBR BXXT.X5N

Mapcode Global: VGYBZ.CPT5

Entry Name: Prehistoric cairn group and field systems on Great Arthur, St Martin's

Scheduled Date: 7 October 1976

Last Amended: 21 January 1999

Source: Historic England

Source ID: 1018616

English Heritage Legacy ID: 15489

County: Isles of Scilly

Civil Parish: St. Martin's

Traditional County: Cornwall

Lieutenancy Area (Ceremonial County): Cornwall

Church of England Parish: Isles of Scilly

Church of England Diocese: Truro


The monument includes a group of seven prehistoric funerary cairns with
adjacent prehistoric field systems on Great Arthur, a small uninhabited island
in the Eastern Isles of the Isles of Scilly.
The cairn group extends as a line over 80m of the island's north east-south
west summit ridge. The north eastern cairn, on raised ground at the end of the
ridge, is a large entrance grave. Two large chambered cairns are similarly
sited on higher ground at the south west end of the group. The ridge between
contains four smaller kerbed platform cairns. All of the cairns are linked by
a wall of a prehistoric field system.
The north eastern entrance grave has a sub-circular mound to 14m in diameter,
rising 1.9m to a flattened top 6m in diameter. A kerb of spaced slabs and
boulders is visible near the foot of the mound. A second kerb bounds the upper
surface and is exposed on the south as a coursed slab wall 0.7m high. The
upper surface contains a subrectangular funerary chamber, 3.6m long, NNE-SSW,
by up to 1.5m wide and 0.7m deep internally, its west side convex. The sides
are walled by at least three courses of laid slabs, with an edge-set slab
closing the southern end. The north end lacks visible closure and a slight
depression in the mound beyond is considered to be the chamber entrance. Three
covering slabs, to 2m long, cross the chamber, one at the south and two
adjacent across the northern half.
The north eastern of the two large cairns at the south west of the ridge has a
mound 10m in diameter, rising 1.7m to a flattened top 6m in diameter; a
perimeter kerb of large slabs is visible on most sides. Its upper surface
contains traces of a funerary chamber, visible as an ovoid hollow 4.5m long,
north-south, by 3.5m wide and 0.7m deep.
The south western cairn in the group has a mound 12m in diameter and up to
1.4m high, incorporating the upper rocks of a natural knoll whose sides drop
steeply from the west of the cairn. It has a flattened upper surface 6m long,
east-west, by 4.5m wide, with indications of a funerary chamber visible in the
north west sector as an ovoid hollow 3m long, north east-south west, by 2m
wide and 0.2m deep; four stones, to 0.2m high, are spaced around its edge.
This cairn is on the island's highest point, marked by a disused Admiralty
triangulation point which now survives as a small modern rubble mound, 0.5m
high, on the north east of the cairn's upper surface.
The other four cairns in the group are spaced 0.5m to 4.5m apart along the
ridge between the larger cairns at each end. Each adjoins the prehistoric wall
following the spine of the ridge and they are located alternately on one side
of the wall then the other, the south western of these small cairns being on
the south east side of the wall. They share similar forms, with rounded mounds
in the range 4m-6.5m in diameter, built out from the slope to 0.25m-0.6m high
on the downslope edges. The mounds have flattened upper platforms, 3m-4.2m in
diameter, defined by small kerb slabs which form a continuous kerb in the
south western of the cairns but which are spaced in the other three. In each
cairn, the curve of its mound, kerb and platform is truncated by the line of
the prehistoric wall.
The wall linking the cairn group forms part of a prehistoric field system, one
of two that subdivide much of the island's land area. The field systems' plots
and linear boundaries are defined by boulder and rubble banks, usually turf
covered and generally 1m-2m wide by 0.5m high, frequently incorporating end-
set slabs called orthostats, 0.2m-1m high, spaced 1m-3m apart along their
midline. Where they roughly follow the contour the banks appear as substantial
steps in the slope profile called lynchets, up to 1m high, whose deposits
often mask their orthostats and whose form reflects soil movement against and
from the original boundaries due to early cultivation on the slope.
On the island's north flank, a row of three rectangular plots is defined by
four banks running upslope from the present coastal edge to end on a large
lynchet at approximately the 10m contour level. This field system is continued
west by another bank extending the line of the lynchet across the lower slope
of the island's north western spur, linking the main hill with a small knoll
at its north west tip. From outcrops on that spur's midslope, another boundary
runs extends WNW down the foot of the steep western slope, a remnant of field
system otherwise truncated by the island's submergence. A higher level
boundary survives along the upper spine of the north western spur, curving
south as it meets the summit ridge to merge with the base of the south western
The prehistoric wall linking the cairns along the summit ridge is the north
western of at least three roughly parallel north east-south west boundaries in
another field system across the island's south east flank, its lower
boundaries being heavily lynchetted. The area is divided into rectangular
plots by at least three walls running downslope, north west-south east: two
descend to the present coastal edge; the third, on the south west, runs along
a spur extending SSE from the island's summit ridge and links the ends of the
north east-south west boundaries. The course of this south western boundary
undergoes a distinct stagger as it passes each north east-south west boundary,
indicating it was secondary in laying out the field system; at its south east
end this boundary is angled to the south west to terminate on a natural
In addition to the field systems, shell midden deposits have also been
recorded from the north east coast of the island and from Arthur Head, on the
island's southern tip.
Beyond this scheduling, broadly contemporary cairn groups and settlement
remains survive on several other islands of the Eastern Isles, including
Middle Arthur and Little Arthur which, with Great Arthur, are now joined by
inter-tidal bars; further field boundaries and house platforms occur on Little
Ganilly nearby to the north. These survivals, now separated by the sea, were
linked by dry land in the landscape contemporary with their construction when
the Eastern Isles formed areas of high ground in the dissected terrain of a
single broad peninsula.

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.

Source: Historic England

Reasons for Scheduling

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'
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.

A variety of prehistoric funerary monuments survives on Scilly, with a
combined date range extending from the later Neolithic to the Middle Bronze
Age (c.2500-1000 BC). Most are formed as funerary cairns constructed as
earth-and-rubble mounds, with flattened tops in the case of platform cairns
and entrance graves, often with a kerb of stones or edge-set slabs around the
mound, platform surface or both. In round and platform cairns, burials were
sometimes accompanied by pottery urns and placed on the old land surface, in
small pits or, on occasion, within a box-like structure of slabs called a cist
which may also be set into the old ground surface or dug into the body of the
cairn. Occasionally, cairns include larger stone-built funerary chambers,
built of edge-set slabs, coursed rubble walling or both, and roofed by large
covering slabs; the chamber may be closed or, in the case of entrance graves,
accessible via a gap in the mound's kerb or outer edge. Each of these forms of
funerary monument can occur singly, in small groups or in larger cemeteries
containing several types. They may also occur in close proximity to
prehistoric field systems and linear boundaries, displaying relationships of
considerable significance for our understanding of the development of land
use, funerary practice and settlement during the prehistoric and later
periods. The field systems so associated may be of various forms, irregular or
regular and enclose large or small plots. The diversity of overall pattern and
detail displayed by these field systems provides valuable insights into the
physical and social organisation of past landscapes.
The prehistoric funerary and settlement elements on Great Arthur survive well,
including a direct physical association between the cairns and a field system.
The diversity of form present among the cairns and the linear arrangement of
the cairn group on the island's ridge give useful insights into the nature of
prehistoric funerary ritual and the important influence of topography on its
physical expression. The influence of underlying landforms is also clearly
apparent in the layout of the field systems, their boundary orientations
generally varying with the slope while several of their delimiting boundaries
follow the crests of the island's main ridge and spurs. The field system
survivals are sufficiently extensive to show the pattern of land division
employed and the deep lynchetting will preserve important old land surfaces,
deposits and features. Although confined to an island by rising sea levels,
the funerary and settlement remains on Great Arthur complement those on the
nearby islands to preserve valuable evidence for the nature and development of
land use in the now largely submerged prehistoric and Roman landscape in the
east of the Scilly archipeligo.

Source: Historic England


Books and journals
Russell, V, Isles of Scilly Survey, (1980)
Thomas, C, Exploration of a Drowned Landscape, (1986)
Thomas, C, Exploration of a Drowned Landscape, (1986)
Cairn SV 91 SW 6D, Quinnell, N V, Ordnance Survey Record & Illustration Cards for SV 91 SW 6, (1978)
Cairn SV 91 SW 6E, Quinnell, N V, Ordnance Survey Record & Illustration Cards for SV 91 SW 6, (1978)
Consulted 1996, CAU, Scilly SMR entry PRN 7220,
Consulted 1996, CAU, Scilly SMR entry PRN 7228,
Quinnell, N V, Ordnance Survey Record Card and Illustration for SV 91 SW 6A, (1978)
Slide 7/688 in ADH slide collection, Hooley, A D, Air photo of the Arthurs taken from south on 23/3/1996, (1996)
Thorpe, C, AM 107 for Scilly SMR entry PRN 7222, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7221.01, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7221.02, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7221.03, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7221.04, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7221.05, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7222, (1988)
Thorpe, C/CAU, AM 107s for Scilly SMR entries for PRN 7221.04-.05, (1988)
Thorpe, C/CAU, AM 107s for Scilly SMR entries PRN 7221.04-.05, (1988)
Title: 1:10000 Ordnance Survey Map; SV 91 SW
Source Date: 1980

Title: Ordnance Survey Record & Illustration Cards for SV 91 SW 6
Source Date: 1978

Source: Historic England

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