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Civil War breastwork and battery 60m east of Carn Nore, St Mary's

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

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Latitude: 49.9159 / 49°54'57"N

Longitude: -6.2819 / 6°16'54"W

OS Eastings: 92732.209498

OS Northings: 10539.28666

OS Grid: SV927105

Mapcode National: GBR BXWX.1DR

Mapcode Global: VGYC5.2CDS

Entry Name: Civil War breastwork and battery 60m east of Carn Nore, St Mary's

Scheduled Date: 9 May 1995

Source: Historic England

Source ID: 1014242

English Heritage Legacy ID: 15359

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 length of defensive bank and ditch, called a
breastwork, dating to the English Civil War, which extends along part of the
north east side of Porth Hellick on the south eastern coast of St Mary's in
the Isles of Scilly. At the ESE end of the breastwork is a Civil War gun
battery, positioned by the north east mouth of the bay.
The breastwork survives as a turf-covered earth and rubble bank, up to 2m wide
and 0.6m high, with slight traces of a ditch, up to 1m wide and 0.1m deep,
along the landward side of the bank. The breastwork extends on an almost
straight WNW-ESE course, running immediately behind the coastal cliff for 30m
between Carn Nore and Porth Hellick Point on the north east side of Porth
Hellick. The WNW end of the breastwork terminates where subsequent erosion of
the coastal cliff has cut across its line. At its ESE end, the breastwork
diverges slightly from the cliff edge to terminate 0.5m before meeting a
second, similar earth and rubble bank which defines the seaward defensive edge
of the battery.
The battery's bank, up to 1.75m wide and 0.5m high, curves south from the
breastwork, returning over 5m to the edge of the coastal cliff, then it curves
again to extend ESE, behind the cliff edge, for a further 8.75m to the point
where another incursion of the cliff has truncated its course.
The breastwork and battery in this monument form part of an integrated system
of Civil War coastal defences which survive extensively around St Mary's. In
the vicinity of this monument, the defensive line along the north east side of
Porth Hellick is continued, from 57m to the WNW, by a second surviving length
of breastwork. A second Civil War coastal gun battery is also located at a
higher level among the outcrops overlooking Porth Hellick Point, 60m ENE of
the battery in this monument.

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.
Civil War fieldworks are earthworks which were raised during military
operations between 1642 and 1651 to provide temporary protection for infantry
or to act as gun emplacements. The earthworks, which may have been reinforced
with revetting or palisades, consist of earth and rubble platforms or banks
and ditches.
The Civil War fieldworks of the Isles of Scilly form a major part of the 150
surviving examples of fieldworks recorded nationally. They present an
unusually complete system of fortifications from this period, both in the
surviving range of fieldwork types represented and in the surviving pattern of
their strategic disposition.
Three main types of Civil War fieldwork have been recognised on the Isles of
Scilly: breastworks, batteries and platforms; these could be deployed
separately or in combination to form a defensive complex.
Breastworks, which on the Isles of Scilly run beside the coastal cliff edge,
consist of an earth and rubble bank, up to 4m wide and nearly 2m high but
generally much smaller, usually accompanied by a ditch on the landward side.
Sixteen surviving examples are recorded on the islands.
Batteries are levelled areas or platforms, generally up to 20m across,
situated on a hilltop or terraced into a slope to serve as gun emplacements.
They vary considerably in size and shape and are usually partially or wholly
enclosed by a bank, occasionally incorporating one or two outer ditches.
Twenty batteries survive on the Isles of Scilly, several connected by
breastworks. Adjacent to some batteries are examples of the third fieldwork
type, platforms. These are partly terraced into, and partly out from, sloping
ground and represent sites of lookouts and temporary buildings. Eight such
platforms, measuring up to 12m by 8m in size, are known to survive on the
islands. These fieldworks and fieldwork complexes were occasionally associated
with other classes of defensive monument on the islands, including earthen
artillery forts and blockhouses.
The fieldworks were designed to defend the deep water approaches to the
islands, especially St Mary's where most examples are found. Fieldworks are
also known from Tresco, Bryher, Samson, St Agnes and Gugh. The circumstances
of their construction are recorded in contemporary historical documents which
indicate most were built by the Royalist forces which controlled the islands
for the entire Civil War period except during 1646-8.

The Civil War breastwork and battery in this monument bordering Porth Hellick
have survived reasonably well. Despite truncation by coastal erosion at each
end of the monument, their situation and the survival of extensive historical
documentation giving the context in which they were built, demonstrate clearly
the strategic methods employed by the Civil War military forces and the
function of breastworks within them. These methods are also well illustrated
by the complementary relationship of this monument to the other surviving
breastwork and battery along the north east side of Porth Hellick.

Source: Historic England


consulted 1994, Waters, A., AM 107 for Scilly SMR entry PRN 7529, (1988)
Title: 1:2500 Ordnance Survey Map; SV 9210
Source Date: 1980

Source: Historic England

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