Prehistoric boundary wall east of Carn Irish, Annet


Heritage Category: Scheduled Monument

List Entry Number: 1014995

Date first listed: 04-Oct-1996


Ordnance survey map of Prehistoric boundary wall east of Carn Irish, Annet
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The building or site itself may lie within the boundary of more than one authority.

District: Isles of Scilly (Unitary Authority)

Parish: St. Agnes

National Grid Reference: SV 85823 08717


Legacy Record - This information may be included in the List Entry Details.

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. 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 submergence.


Legacy Record - This information may be included in the List Entry Details.


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.

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.


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

Legacy System number: 15447

Legacy System: RSM


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 Author: Publisher: Surveyor:

End of official listing