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.
Platform cairns are funerary monuments of Early Bronze Age date (c.2000-1600
BC). They were constructed as low flat-topped mounds of stone rubble, up to
40m in external diameter though usually considerably smaller, covering single
or multiple burials. Some examples have other features, including peripheral
banks and internal mounds constructed on the platform. A kerb of slabs or
edge-set stones sometimes bounds the edge of the platform, and a peripheral
bank or mound if present. Platform cairns can occur as isolated monuments, in
small groups or in cairn cemeteries. In cemeteries they are normally found
alongside cairns of other types.
Platform cairns form a significant proportion of the 387 surviving cairns on
the Isles of Scilly; this is unusual in comparison with the mainland. All
surviving examples on the Isles of Scilly are considered worthy of protection.
The platform cairn and house platform settlement at Pernagie survive well; the
settlement site has not been excavated and despite remains from much later
structures causing some modification to the cairn's upper surface, the
disturbance is limited and evidence still survives for the cairn's underlying
funerary structure. This cairn and settlement are an unusual survival within
low-lying areas enclosed during the post-medieval period and consequently they
are of considerable value for our understanding of prehistoric land use at
these levels, complementing the evidence from the more extensive survivals on
higher land as on the neighbouring Top Rock Hill.
Details
The monument includes a prehistoric platform cairn and nearby settlement and
field system on a small knoll at the south of Pernagie, a low coastal strip on
the north west coast of St Martin's in the Isles of Scilly. The prehistoric
features occur within the area of a largely dismantled post-medieval field
system, with remains of a small building built onto the cairn. The scheduling
also includes an area of prehistoric field system to the west of the cairn.
The cairn is visible on the summit of the knoll as a roughly circular mound
13m in diameter, rising 1.5m high from the knoll's steep northern slope but
only 0.3m from the crest of the knoll on the south to a flattened upper
platform approximately 5m in diameter. In the ESE of the upper surface is a
small bedrock outcrop, 0.7m high, and along the southern edges of the platform
a curving line of spaced small bedrock outcrops project from the turf to give
the effect of a spaced kerb, supplemented on the south east by an artificially
edge-set slab.
The centre and eastern half of the mound's upper surface contain the lower
course and adjacent tumble of slab-built walling deriving from a small early
post-medieval building founded upon remains of the cairn's funerary structure.
The building's remains include, east of centre on the cairn, a north-south
wall of four edge-set slabs, to 1.2m long and 1m high, ending on the south at
a corner with another edge-set slab extending west. Within the wall's corner
is a fallen slab but embedded in the turf beyond it, the upper edges of a line
of further buried slabs extend north for 2.75m, parallel with, and 1.5m west
of, the exposed north-south wall. The rectangular arrangement across the
cairn's centre formed by the exposed walling and the buried line of slabs
closely resembles in size and position the box-like funerary structures called
cists known from several other prehistoric cairns on Scilly. Along the east of
the building's exposed wall is a hollow 1.3m wide and 0.7m deep, fringed on
the east side by tumbled wall slabs; the hollow is constricted at the south by
the small bedrock outcrop, from which a ridge of exposed rubble runs west to
the building's wall corner.
Beyond the building, the north east periphery of the cairn's mound is
over-ridden by the corner of a post-medieval field wall which extends to the
north and ENE.
The prehistoric settlement site is situated on the lower south eastern slope
of the knoll, from about 15m south east of the platform cairn. It is visible
as a close grouping of at least two house platforms, each visible with an
ovoid interior approximately 7m long by 5m wide, levelled into the lower slope
to give a steep backscarp generally 1.5m high and bearing traces of a rubble
revetment facing. Opposite the backscarp, the forward edge of their interiors
are defined by a rubble wall up to 1.5m wide and 0.5m high from the platform
interior but dropping 1.5m externally.
The prehistoric cairn and settlement, and the post-medieval building, occur
within a post-medieval field system depicted on 19th and early 20th century
Ordnance Survey maps but extensively dismantled and robbed of its wall stone
since then. In addition to its upstanding walling on the north east periphery
of the cairn as noted above, and further such walling on the eastern slope of
the knoll, surviving traces of an earlier, prehistoric, field system include
slight turf-covered banks extending 10m west from the cairn's southern edge
and along the upper southern slope of the knoll to meet another slightly
angled bank crossing the low ridge west of the knoll, heading north over its
northern half and south west over its southern half. A further low bank
extends 15m west along the ridge's spine from the angle in the bank across the
ridge; near its western end it incorporates a cluster of natural outcrops,
beyond which it turns SSW towards the headland's southern coast.
Beyond this scheduling, a cairn cemetery associated with prehistoric field
systems and settlement sites extend across Top Rock Hill and its flanks, the
neighbouring upland area to the east on St Martin's.
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.
