Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Kerbed platform cairn and prehistoric house platform 370m NNW of the Pest House, St Helen's

A Scheduled Monument in Tresco, Isles of Scilly

Approximate Location Map
Large Map »
Street or Overhead View
Contributor Photos »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 49.9742 / 49°58'26"N

Longitude: -6.3263 / 6°19'34"W

OS Eastings: 89916.407019

OS Northings: 17194.019995

OS Grid: SV899171

Mapcode National: GBR BXRR.C21

Mapcode Global: VGYBR.9XD6

Entry Name: Kerbed platform cairn and prehistoric house platform 370m NNW of the Pest House, St Helen's

Scheduled Date: 21 May 1996

Source: Historic England

Source ID: 1014552

English Heritage Legacy ID: 15433

County: Isles of Scilly

Civil Parish: Tresco

Traditional County: Cornwall

Lieutenancy Area (Ceremonial County): West Yorkshire

Church of England Parish: Isles of Scilly

Church of England Diocese: Truro


The monument includes a prehistoric kerbed platform cairn and a nearby
habitation site, called a house platform, situated on the north western
coastal slope of St Helen's, an uninhabited island in the north of the Isles
of Scilly.
The cairn and the house platform are situated 20m apart on a north-south axis.
The southernmost of the two, the cairn, survives with a circular mound of
heaped rubble, 5.5m in diameter and up to 0.25m high on the north west side.
The mound rises to a flattened platform, 4m in diameter and tilted slightly to
the west in conformity with the surrounding slope. The platform perimeter is
defined by a kerb of at least seven spaced slabs, most of which lie flat but
they include two edge-set slabs: the largest on the west is 0.6m long and 0.3m
high; the smaller slab, on the south, is 0.25m high.
To the north of the cairn, the house platform is visible as a distinct ovoid
hollow measuring 7m north east-south west by up to 6m north west-south east,
cut into the fairly steep north west facing slope. The south eastern, rear,
edge of the platform is cut 0.4m deep into the slope while a bank of similar
height extends along the platform's north western edge.
Beyond this monument, another kerbed platform cairn is located 35m to the
east, while a further two similar cairns are located 110m to the SSE and a
large round cairn containing a funerary cist is situated on the island's
summit. Prehistoric field systems also occur on the island's lower western
slopes and on the upper slope to the east of the summit. These broadly
contemporary features are the subject 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.

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. Current evidence indicates that
nationally, but excluding Scilly, there are under 250 known examples of this
monument class. On the Isles of Scilly, platform cairns form one of the
recurrent types of small cairn represented in cairn cemeteries - an unusual
and distinctive expression of this monument class, which forms a high
proportion of the 387 surviving cairns recorded on the islands.
By contrast, house platforms are one of several known types of settlement site
dating from the Neolithic to the early medieval periods (from c.4000 BC to
c.AD 1000). Individual house platforms may be dated by excavation or by their
association with other monuments of known date. They consist of levelled
stances, variously circular, ovoid or sub-rectangular in shape, on which
similarly varied shapes of building were constructed. This broadly defined
class of monument exhibits considerable variety of form nationally, largely
depending on the nature and context of the buildings they supported and
whether the platform was wholly or only partly occupied by the floor of the
building. On the Isles of Scilly, house platforms tend to survive as rounded
or oval levelled stances cut into hillslopes or into the scarps of field
terraces. The stances are often provided with a bank or wall along the outer
lip of the platform, thereby creating a hut circle built in an economical
manner by using the levelling backscarp as a major part of the wall. Indeed a
gradation can be drawn on Scilly from non-freestanding house platforms to
fully freestanding hut circles. Excavations have confirmed the dating of house
platforms on Scilly from at least the Bronze Age to the early medieval period,
concurrent with more conventionally-built hut circles of round and ovoid forms
on the islands. House platforms on Scilly may occur singly or in groups,
unenclosed in the open or intimately associated with broadly contemporary
field systems. House platforms form a significant proportion of the 140 hut
circles and related forms of settlement site recorded on Scilly and by their
nature they form the normal expression of prehistoric to early medieval
settlement in steeper slope locations.
The platform cairn and house platform in this monument have survived well and
neither has been excavated. The close proximity of these respective funerary
and settlement elements emphasises the varied uses which this exposed terrain
has served from the prehistoric to medieval period, while the physical
relationship between the cairn and the nearby prehistoric field systems
typifies the organisation of land use during the Bronze Age.

Source: Historic England


consulted 1988, Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7114, (1988)
consulted 1988, Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7266, (1988)
consulted 1988, Parkes, C/CAU, AM 107s for Scilly SMR entries PRN 7112-3, (1988)
consulted 1995, Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7114, (1988)
consulted 1995, Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7267.04, (1988)
consulted 1995, Parkes, C/CAU, AM 107s for Scilly SMR entries PRN 7112-3, (1988)
Title: 1:10000 Ordnance Survey Maps: SV 81 NE & SV 91 NW
Source Date: 1980

Source: Historic England

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.