Prehistoric entrance grave, the northern one of three on Cruther's Hill, St Martin's


Heritage Category: Scheduled Monument

List Entry Number: 1013803

Date first listed: 07-Oct-1976

Date of most recent amendment: 25-Jan-1996


Ordnance survey map of Prehistoric entrance grave, the northern one of three on Cruther's Hill, St Martin's
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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. Martin's

National Grid Reference: SV 92890 15219

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. Entrance graves are funerary and ritual monuments whose construction and use dates to the later Neolithic, Early and Middle Bronze Age (c.2500-1000 BC). They were constructed with a roughly circular mound of heaped rubble and earth, up to 25m in diameter, whose perimeter may be defined by a kerb of edge-set slabs or, occasionally, coursed stone. The mound contains a rectangular chamber built of edge-set slabs or coursed rubble walling, or a combination of both. The chamber was roofed by further slabs, called capstones, set across the chamber. The chamber was accessible via a gap in the mound's kerb or outer edge and often extends back beyond the centre of the mound. The cairn's mound and chamber may incorporate natural boulders and outcrops. Excavations in entrance graves have revealed cremated human bone and funerary urns, usually within the chambers but on occasion within the mound. Unburnt human bone has also been recovered but is only rarely preserved. Some chambers have also produced ritual deposits of domestic midden debris, including dark earth typical of the surface soil found within settlements, animal bone and artefact fragments. Entrance graves may occur as single monuments or in small or large groups, often being associated with other cairn types in cemeteries. They may also occur in close proximity to broadly contemporary field boundaries. The national distribution of entrance graves is heavily weighted towards the Isles of Scilly which contain 79 of the 93 surviving examples recorded nationally, the remaining 14 being located in western Cornwall.

This entrance grave on Cruther's Hill has survived well. Despite limited surface disturbance evident around the top of the funerary chamber, it retains a good range of original features, including an unusually complete slab-built kerb. The prominent siting of this monument demonstrates the important role played by landscape features in the beliefs and perception of prehistoric communities, a point reinforced by the monument's proximity to the other prehistoric funerary monuments along the summit ridge of Cruther's Hill. The wider organisation of prehistoric land use and the later profound changes in landscape context are illustrated by the monument's relationship with the prehistoric cists and settlement sites in the inter-tidal zone to the east and west of Cruther's Hill.


The monument includes a prehistoric entrance grave situated on the northern end of the summit ridge of Cruther's Hill, on the south coast of St Martin's in the Isles of Scilly. The entrance grave survives with a circular mound of heaped earth and rubble, 16.5m in diameter and up to 2m high, its height accentuated by its location on a natural knoll at the northern end of the hill's narrow summit ridge. A large slender slab, 2.3m long, 0.5m wide and 0.75m high, lies north east-south west on the north east slope of the mound and is considered to have been displaced from the top of the mound. At least two large slabs also protrude through the vegetation on the mound's periphery on the SSW side. The mound rises to a flattened platform defined by a polygonal kerb of near contiguous large slabs, up to 1.9m long and 1.6m high, mostly edge-set. The kerb measures 9m north-south by 9.5m east-west externally, incorporating an outcrop of bedrock granite on the WSW side which projects 1.5m beyond the kerb's line. Slabs from the upper part of a rectangular funerary chamber are visible in the surface of the platform's southern sector. The full extent of the chamber is partly masked by disturbance of the surface and evident displacement of some rubble. The slabs extend over 3.5m north-south, ending at a bedrock outcrop rising to the platform surface on the north side and blocked at its southern entrance by slabs along the kerb line. The visible slabs show some disruption from their original arrangement but they include the upper surface of an edge-set slab from the chamber's east wall and other slender slabs laid across the chamber width, the largest of which, 1.6m long, is considered to be one of the chamber's original covering slabs. This is one of the earliest prehistoric monuments on the Isles of Scilly to receive historical mention; the antiquary Borlase noted the funerary cairns on Cruther's Hill when he visited St Martin's in 1752. He specifically describes a large slab lying on the north east side of this monument's mound, believing, without stated cause, that it formerly stood erect as a standing stone. This entrance grave is one of a linear group of four broadly contemporary funerary monuments dispersed along 130m of the summit ridge of Cruther's Hill. This is a highly prominent cairn group which is visible over considerable distances to the east and west. A further funerary cairn is located 120m NNW of this monument, in the saddle between Cruther's Hill and Higher Town. Small prehistoric box-like funerary chambers, called cists, are known from now submerged locations overlooked by Cruther's Hill to both east and west, while those cists to the east are also accompanied by broadly contemporary settlement sites on the sloping beach of Higher Town Bay.

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: 15416

Legacy System: RSM


Books and journals
Ashbee, P, Ancient Scilly, (1974)
Ashbee, P, Ancient Scilly, (1974)
Ashbee, P, Ancient Scilly, (1974)
Borlase, W, Observations on Ancient and Present State of the Isles of Scilly, (1756)
Borlase, W, Observations on Ancient and Present State of the Isles of Scilly, (1756)
Russell, V, Isles of Scilly Survey, (1980)
Russell, V, Isles of Scilly Survey, (1980)
Rees, S, AM7 scheduling documentation for CO 992, 1975, Cairn 'a'
Rees, S, AM7 scheduling documentation for CO 992, 1975, consulted 1995
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7170, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7172, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7172.01, (1988)
Thorpe, C/CAU, AM 107 for Scilly SMR entry PRN 7301, (1988)
Thorpe, C/CAU, AM 107s for Scilly SMR entries PRN 7147, 7302-3, (1988)
Thorpe, C/CAU, AM 107s for Scilly SMR entries PRN 7148, 7178, (1988)
Title: 1:2500 Ordnance Survey Map: SV 9215 Source Date: 1980 Author: Publisher: Surveyor:
Title: 1:2500 Ordnance Survey Map; SV 9215 Source Date: 1980 Author: Publisher: Surveyor:

End of official listing