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Two kerbed platform cairns 50m north of Porth Morran, White Island

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

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Latitude: 49.9785 / 49°58'42"N

Longitude: -6.2931 / 6°17'35"W

OS Eastings: 92324.637669

OS Northings: 17542.674645

OS Grid: SV923175

Mapcode National: GBR BXVQ.VNM

Mapcode Global: VGYBR.VSYT

Entry Name: Two kerbed platform cairns 50m north of Porth Morran, White Island

Scheduled Date: 7 October 1976

Last Amended: 20 February 1995

Source: Historic England

Source ID: 1010158

English Heritage Legacy ID: 15393

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 two prehistoric kerbed platform cairns situated on the
lower southerly slope of the northern hill of White Island, off St Martin's in
the Isles of Scilly. The cairns are located near the centre of a group
containing at least nine prehistoric cairns of various types dispersed over
the northern half of White Island. These cairns are situated 12m apart on a
NNE-SSW axis.

The southern platform cairn survives with a circular mound of heaped rubble,
5.5m in diameter, rising 0.35m high to a flattened upper platform, 3.5m in
diameter. The perimeter of the platform is marked by a kerb of five large end-
and edge-set slabs, up to 0.65m high and 0.5m wide, spaced 1m-1.5m apart. One
of the slabs has fallen outwards to the south. Several smaller slabs are
visible along the kerb line between the large spaced slabs.

The northern platform cairn also survives with a circular mound of heaped
rubble, 5.5m in diameter, rising to a flattened upper platform, 2m in
diameter. The platform is levelled on the southerly slope such that it is 0.3m
high from the south side and merges with the slope on the north. The perimeter
of the platform has a partial kerb of low slabs projecting through the turf on
its south and south east sides. At the centre of the platform are two
projecting slabs, up to 0.5m long and 0.15m high. The north eastern periphery
of this cairn's mound has been truncated by a partly silted modern trench, 1m
wide and 0.3m deep, with a low bank of upcast along its south west side. This
trench was dug as one of several firebreaks across the slope.

Although these cairns are located on what is now a fairly small uninhabited
island, linked to the much larger St Martin's island at low tide, the physical
environment in which they were originally built was on a broad rocky
promontory, facing a broad valley to the south, on the northern edge of the
single large island that formerly united much of the area of the present Isles
of Scilly archipelago, from St Mary's northwards. The gradual sinking of the
land since this cairn was constructed has led to the fragmentation of that
island into the present scatter of large and small islands and rocks. Other
broadly contemporary funerary cairns in this dispersed group on northern White
Island are located from 22m to the west and 40m to the north, while
prehistoric field systems are located from 90m to the south west and 140m to
the south east on the central and southern parts of the island, extending onto
the upper shore of Porth Morran as a result of the submergence.

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.
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.

These two kerbed platform cairns on White Island have survived well, despite
the clipping of the northern cairn by the firebreak trench, and they have not
been archaeologically excavated. The relationships between this monument, the
other varied types of funerary cairn and the prehistoric field system on White
Island, and the known submergence of the land since they were built,
illustrate in a dramatic way the major environmental changes that have
affected the setting of some surviving prehistoric monuments since their
construction and show the diversity of funerary practices and the organisation
of land use among prehistoric communities.

Source: Historic England


Books and journals
Grigson, G, The Scilly Isles, (1977)
Russell, V, Isles of Scilly Survey, (1980)
Russell, V, Isles of Scilly Survey, (1980)
Thomas, C, Exploration of a Drowned Landscape, (1985)
Thomas, C, Exploration of a Drowned Landscape, (1985)
Thomas, A C, 'Cornish Archaeology' in Recent Fieldwork in the Isles of Scilly, , Vol. 14, (1975), 87-94
consulted 1994, Thorpe, C., AM 107 for Scilly SMR entry PRN 7097.04, (1988)
consulted 1994, Thorpe, C., AM 107 for Scilly SMR entry PRN 7097.05, (1988)
consulted 1994, Thorpe, C., AM 107 for Scilly SMR entry PRN 7099, (1988)
consulted 1994, Thorpe, C., AM 107s for Scilly SMR entries PRN 7096-7, (1988)
Rees, S.E., AM7 scheduling documentation for CO 998, 1975, Cairn 'c'. Consulted 1994
Rees, S.E., AM7 scheduling documentation for CO 998, 1975, Cairn 'd'. Consulted 1994
Title: 1:10000 Ordnance Survey Map; SV 91 NW
Source Date: 1980

Source: Historic England

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