Ancient Monuments

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Prehistoric boundary wall east of Carn Irish, Annet

A Scheduled Monument in St. Agnes, Isles of Scilly

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Latitude: 49.896 / 49°53'45"N

Longitude: -6.3763 / 6°22'34"W

OS Eastings: 85823.289072

OS Northings: 8717.042095

OS Grid: SV858087

Mapcode National: GBR BXNY.L5B

Mapcode Global: VGYC3.FWG3

Entry Name: Prehistoric boundary wall east of Carn Irish, Annet

Scheduled Date: 4 October 1996

Source: Historic England

Source ID: 1014995

English Heritage Legacy ID: 15447

County: Isles of Scilly

Civil Parish: St. Agnes

Traditional County: Cornwall

Lieutenancy Area (Ceremonial County): Cornwall

Church of England Parish: Isles of Scilly

Church of England Diocese: Truro


The monument includes a prehistoric linear boundary wall extending to Carn
Irish on the western peninsula of Annet, an uninhabited island in the south
west of the Isles of Scilly.
The linear boundary wall survives with a contiguous line of boulders up to 1m
wide and 1m high, extending on an almost straight course for at least 25m ESE
from the foot of Carn Irish, a prominent jagged outcrop near the western tip
of the peninsula. At least two of the wall's slabs are edge-set. The boundary
runs to the north of the peninsula's midline, converging on the present
shoreline of North West Porth whose pre-submergence occupation is considered
to have been delimited by this monument. Towards the boundary's eastern end,
it becomes progressively engulfed and eventually masked altogether beneath the
deep thrift turf that blankets this part of the island, reaching a thickness
of 0.6m at the eastern visible extent of the wall.
Beyond this monument, other broadly contemporary settlement remains on Annet
include large middens of occupation debris on each side of West Porth, from
340m to the ESE, and a field system with hut circles on south eastern Annet,
from 580m to the south east. Near the summit of the island's northern hill is
a kerbed platform cairn, 280m to the north east. All of these archaeological
features are the subjects of separate schedulings.

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.
The early linear boundaries on the Isles of Scilly were constructed from the
Bronze Age to the early medieval period (c.2000 BC-AD 1066): closer dating
within that period may be provided by their visible relationships to other
classes of monument, or by their relationship with an earlier recorded sea
level. They consist of stone walls, up to 3m wide and 1.1m high but usually
much slighter, and are formed of heaped rubble, often incorporating edge- or
end-set slabs called orthostats.
Linear boundaries served a variety of functions. These included separating
land regularly cultivated from that less intensively used, separating land
held by different social groups, or delineating areas set aside for
ceremonial, religious and funerary activities. Linear boundaries are often
associated with other forms of contemporary field system. The Isles of Scilly
contain examples of an associaton, rarely encountered elswhere, whereby
certain linear boundaries directly link several cairns, entrance graves and
cists in some groups of prehistoric funerary monuments.
Linear boundaries along the coastal margin of the islands are often
indistinguishable from the truncated upper walls of early field systems whose
remaining extent has been destroyed by the rising sea level. Linear boundaries
form a substantial part of the evidence of early field systems recorded on the
Isles of Scilly. They provide significant insights into the physical and
social organisation of past landscapes and form an important element in the
existing landscape. Even where truncated by the rising sea level, their
surviving lengths provide important evidence for the wider contemporary
context within which other nationally important monuments at higher altitudes
were constructed. A substantial proportion of surviving examples are
considered worthy of protection.

This linear boundary on Annet survives well, without any known disturbance,
and by its alignment on the prominent Carn Irish outcrop it displays well the
influence of distinctive natural features in the organisation of prehistoric
land use. Although its adjoining contemporary settlement areas have been
truncated by rising sea levels, this boundary provides valuable evidence for
the wider nature and extent of the pre-submergence land use that formed the
context of the important prehistoric settlement and middens to the south east
on this island. The unusually deep thrift turf that engulfs much of this
boundary and obscures its eastward continuation will also embody a valuable
source of environmental information relating to the islands' gradual

Source: Historic England


Books and journals
Borlase, W, Observations on Ancient and Present State of the Isles of Scilly, (1756)
Grigson, G, The Scilly Isles, (1977)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7048, (1988)
Parkes, C/CAU, AM 107s for Scilly SMR entries PRN 7046, 7047, 7050, (1988)
Title: 1:10000 Ordnance Survey Map, SV 80 NE
Source Date: 1980

Source: Historic England

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