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Prehistoric field system and stone setting, Civil War fieldworks, post medieval kelp pits and quay on Toll's Island, St Mary's

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

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Latitude: 49.9288 / 49°55'43"N

Longitude: -6.2787 / 6°16'43"W

OS Eastings: 93042.220398

OS Northings: 11961.83342

OS Grid: SV930119

Mapcode National: GBR BXWW.2VQ

Mapcode Global: VGYC5.412W

Entry Name: Prehistoric field system and stone setting, Civil War fieldworks, post medieval kelp pits and quay on Toll's Island, St Mary's

Scheduled Date: 7 October 1976

Last Amended: 21 January 1999

Source: Historic England

Source ID: 1015660

English Heritage Legacy ID: 15474

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 and stone setting, together
with adjacent breastworks and a gun battery dating to the English Civil War on
Toll's Island, a small island linked at low tide levels to the north east
coast of St Mary's in the Isles of Scilly. The monument also includes four
post-medieval kelp pits behind the island's southern coast; the kelp pits are
associated with a small quay, also included within the monument, near the
island's western tip.
The field system divides much of the island into subrectangular blocks by
fairly straight boundaries, visible as slight rubble walls, up to 1m wide and
0.2m high, mostly masked beneath the turf. The walls incorporate a midline row
of edge- or end-set slabs, generally 0.5m-0.6m high and spaced 1m-2m apart.
The field system has a spinal wall running approximately 75m ENE-WSW along the
island's summit crest and western slope, from the much later Civil War battery
on the highest land at the east to a relatively recent enclosure wall on the
north western lower slope. On the west of the island's summit crest, the
spinal wall is interrupted by the scattered upstanding slabs of a small
granite outcrop embellished to give the stone setting described below. From
the west of that break a wall runs SSE then turns ESE along the upper southern
slope to form the top boundary of a row of rectangular fields defined by at
least three further walls running SSW directly down the island's southern
flank. On the island's northern flank, the end walls of the recent enclosure
occupying the north west slope also run directly downslope and are considered
to reuse courses of the prehistoric plot boundaries.
The stone setting west of the island's summit, and respected by the break in
the field system's spinal wall, is visible as a group of five narrow
upstanding slabs, up to 1.3m long, 0.9m high and 0.8m thick, their long axes
oriented ENE-WSW and arranged in two lines north and south of a rectangular
area 5m long, east-west, by 2.3m wide. At least two slabs appear as natural
bedrock protrusions, embellished to produce the artificial setting by the
addition of the other edge-set slabs; one of the latter leans inwards at the
centre of the north side, while another, on the south east of the setting,
shows traces of a slight rubble mound around its base.
During the English Civil War, from 1642 to 1651 on Scilly, Toll's Island
became a focus of fortification by virtue of its strategic position at the
entrance to Crow Sound, a main maritime route into the archipeligo, and
because of the sheltered landing place offered by Pelistry Bay in which the
island lies. The surviving fieldworks reflect both aspects. A large gun
battery, known as Pellew's Redoubt, was built on the island's highest point
behind its north east coast, giving a field of fire across Crow Sound and its
approach from the east. The battery is kidney-shaped in plan to give two
forward flanks, facing east and north west. It survives as a raised platform
of earth and rubble, 22m long, north east-south west, by up to 13m wide
externally, its outer scarp rising to 1.5m high to a perimeter bank, 4m wide,
around a levelled interior whose surface is approximately 1m above the
surrounding ground level. Occasional facing slabs are visible on the outer
scarp, which dips on the west to give an entrance gap 1.3m wide. Slight quarry
hollows are visible beyond the south east and north west of the battery.
The battery is complemented by two lengths of breastwork as defences against
enemy landings; each is visible as an earth and rubble bank parallel with, and
close to, the coastal cliff and backed by a shallow ditch. One breastwork
extends for 23m along the western half of the island's south coast; the other
runs for 26m behind the north east coast, from near Pellew's Redoubt to a
prominent outcrop to the south east.
Along the island's lower southern flank is a row of four kelp pits, sites
where gathered seaweed was burnt to give soda ash in a local industry lasting
from 1684 to 1835, supplying the resulting product to the mainland glass, soap
and alum industries. The kelp pits are unevenly spaced over approximately 75m
in an ESE-WNW line, from 0.1m to 15m behind the cliff edge. They survive as
inverted-cone shaped hollows, ranging from 1.3m to 1.6m in diameter and 0.4m
to 0.6m deep, lined by slabs generally 0.3m-0.5m across with one laid flat at
the base, but employing distinctly smaller slabs in the eastern kelp pit. Some
slabs have reddened and degraded surfaces from their former heating; two pits
have a slight raised lip of slabs, to 0.1m high, around their perimeter, and
two have a scatter of small slabs up to 2m from their edges, considered to be
discarded fragments of old pit linings.
To the south of the island's western tip are remains of a small quay in the
inter-tidal zone, long-disused but one of several such quays closely
associated with sites of kelp pits on Scilly. The quay is up to 3m wide, 1.5m
high and 19m long, running south from the dense boulder spread on the middle
shore then curving south west and tapering to end at a large boulder with an
iron mooring ring set in its top. Another such boulder set with a mooring ring
is located in the bay several metres south of the quay's tip. The quay has a
boulder core faced by roughly coursed boulder walling. From the upper end of
the quay, a broad track runs east onto the upper shore; it is 2.75m-3.5m wide,
cleared through the shore rubble and defined by up-ended boulders but it is
now partly inundated by boulders subsequently washed in and its course is
disrupted by wave action 10m before reaching the present coastal cliff of the
island. Near the junction of the track with the quay is another boulder set
with an iron ring.
The prehistoric field system and Civil War fieldworks in this scheduling
complement other contemporary remains on the nearby coast of St Mary's. The
field system is inter-visible with another prehistoric field system on Mount
Todden, 350m to the south west across Pelistry Bay but formerly linked by dry
land in the pre-submergence landscape when these field systems were laid out
and used. The Civil War fieldworks on Toll's Island formed an integral part of
a defensive system that extended around the coast of St Mary's, including two
gun batteries on Mount Todden to the south and two on Toll's Hill to the north
west; Toll's Hill also contains two Civil War platforms and a coastal
breastwork, from 250m north west of this scheduling.

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.

The prehistoric, Civil War and post-medieval elements in this scheduling on
Toll's Island each survives well. The prehistoric field system displays
clearly its pattern and relationship to the topography while the nearby field
system on Mount Todden illustrates its wider prehistoric context, giving
valuable evidence for the organisation of land use in the pre-submergence
landscape of the islands. The stone setting, respected by the field system
walls, is a very rare prehistoric ritual structure known from some upland
areas on the mainland and unique on Scilly. The situations of the battery and
breastworks on Toll's Island and their wider context within the extensive
surviving Civil War defensive system on Scilly demonstrates clearly the
strategic methods employed by the mid-17th century military forces and the
function of these fieldwork types within them. This scheduling also contains
the largest surviving group of kelp pits on Scilly and shows well their
characteristic form, features and coastal location near the rocky shores
productive of the seaweed they consumed. Their association with the abandoned
quay and its trackway in this scheduling illustrates the main range of
surviving elements of the kelp industry, a major contributor to the islands'
economy in the early post-medieval period.

Source: Historic England


Books and journals
Over, L, The Kelp Industry in Scilly, (1987)
Over, L, The Kelp Industry in Scilly, (1987)
Over, L, The Kelp Industry in Scilly, (1987)
Norway, A H, 'The Cornish Magazine' in The heroic actions of Lord Exmouth, , Vol. I, (1898), 375-388
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7232, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7233.01, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7233.02, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7233.03, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7237, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7238, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7239, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7646, (1988)
Rees, S E, AM7 for Scilly County Monument SI 1024, (1975)
Title: 1:10000 Ordnance Survey Map; SV 91 SW
Source Date: 1980

Title: 1:2500 Ordnance Survey Map; SV 91 SW
Source Date: 1980

Title: 25": 1 mile Ordnance Survey Map; Cornwall sheet LXXXVII
Source Date: 1908

Source: Historic England

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