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Prehistoric field system east of Peninnis Head lighthouse, St Mary's

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

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Latitude: 49.905 / 49°54'18"N

Longitude: -6.3028 / 6°18'9"W

OS Eastings: 91161.56048

OS Northings: 9411.833833

OS Grid: SV911094

Mapcode National: GBR BXTY.3TB

Mapcode Global: VGYC4.PNV5

Entry Name: Prehistoric field system east of Peninnis Head lighthouse, St Mary's

Scheduled Date: 4 October 1996

Source: Historic England

Source ID: 1014992

English Heritage Legacy ID: 15467

County: Isles of Scilly

Civil Parish: St. Mary's

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 field system extending along the coastal
flank at the tip of Peninnis Head, a broad promontory on the south coast of St
Mary's in the Isles of Scilly.
The field system is defined by rubble banks, up to 1.5m wide and 0.5m high,
generally turf-covered but most lengths incorporate a row of projecting spaced
boulders and edge-set slabs, up to 1.25m long, 0.7m high and commonly 1m-3m
apart. Where the banks run along the slope they appear as marked steps, called
lynchets, caused by soil movement on the gradient against the banks' uphill
sides and away from their downhill sides, a process accelerated by early
The field system's boundaries define two subrectangular plots which adjoin end
to end along the upper coastal slope, their layout strongly influenced by the
underlying terrain. Their north east - south west long axes extend along the
contour, while the upper ends of the field system's three downslope walls
terminate on natural bedrock outcrops and a massive natural boulder.
The south western plot measures 68m long, north east - south west, by up to
38m wide; its south west wall rises to a large bedrock exposure that abuts and
defines much of this plot's south west end. Its north east end wall ascends
the slope, beside a steep scarp to its north east, and continues for a further
5.5m beyond the upper corner of the plot to terminate on a prominent natural
Beyond that north east end-wall and the scarp alongside it, the adjoining
prehistoric plot occupies a broad natural hollow facing south east, its rear
defined by the steep scarp. The plot makes use of the hollow's gently sloping
floor for its interior. It is defined across the south east, open, side of the
hollow by a wall 60m long, extending north east from the adjacent plot's south
east wall and curving north over its final 16m to run to a large outcrop at
the far end of the hollow. The foot of the steep scarp defining its western
and northern sides results in a plot measuring c.40m wide.
Beyond this monument, another area of prehistoric field system of similar
character occupies the eastern coastal flank of Peninnis Head, from 90m to the
north east. This monument is considered to be an outlier from that field
system, exploiting a usable pocket of land on the largely rocky flanks at the
end of the promontory. By contrast, a broadly contemporary cemetery of
funerary cairns is dispersed about the summit area of the promontory's tip,
the nearest being situated 30m north of the monument. These cairns 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.
Regular field systems are one of several methods of field layout known to have
been employed in the Isles of Scilly from the Bronze Age to the Roman period
(c.2000 BC - AD 400); closer dating within that period may be provided by the
visible relationships of the field boundaries to other classes of monument
with a shorter known time-span of use, or by their relationship with an
earlier recorded sea level.
They comprise a collection of field plots defined by boundaries laid out in a
consistent manner, along two dominant axes at approximate right angles to each
other. This results in rectilinear fields which may vary in their size and
length:width ratio both within and between individual field systems. The
fields are bounded by rubble walls or banks, often incorporating edge- or end-
set slabs called orthostats. Within its total area, a regular field system may
be subdivided into blocks differing in the orientations of their dominant
Regular field systems may be associated with broadly contemporary settlement
sites such as stone hut circles. Some regular field systems on the Isles of
Scilly contain a distinctive association, rarely encountered elsewhere,
whereby certain of their field boundaries directly incorporate or link cairns,
entrance graves and cists in some groups of prehistoric funerary monuments.
Although no precise figure is available, regular field systems form one of the
three principal forms of prehistoric field system, along with irregular field
systems and some groups of prehistoric linear boundaries, which survive in
over 70 areas of the Isles of Scilly. They provide significant insights into
the physical and social organisation of past landscapes and they provide
evidence for the wider contemporary context within which other nationally
important monuments were constructed.

This prehistoric field system on the tip of Peninnis Head survives well,
clearly displaying the character of the prehistoric land division and the
strong influences upon it of the natural topography. Its broader prehistoric
land use context is illustrated by the field system survivals on the east
flank of the promontory and by the cairn cemetery about the summit. Its
relationship with that cairn cemetery also demonstrates the wider manner in
which farming and funerary activities were organised among the prehistoric
communities that used this field system.

Source: Historic England


SW area of field system in SMR entry, Waters, A/CAU, AM 107 for Scilly SMR entry PRN 7419, (1988)
Title: 1:2500 Ordnance Survey Map; SV 9109
Source Date: 1980

Waters, A/CAU, AM 107 for Scilly SMR entry PRN 7420, (1988)

Source: Historic England

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