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Prehistoric field system and post-medieval breastwork and maze on Castella Down, St Agnes

A Scheduled Monument in St. Agnes, Isles of Scilly

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Latitude: 49.8897 / 49°53'22"N

Longitude: -6.3519 / 6°21'6"W

OS Eastings: 87535.063365

OS Northings: 7910.305474

OS Grid: SV875079

Mapcode National: GBR BXPZ.CB9

Mapcode Global: VGYC9.V1CF

Entry Name: Prehistoric field system and post-medieval breastwork and maze on Castella Down, St Agnes

Scheduled Date: 4 October 1996

Last Amended: 8 April 1997

Source: Historic England

Source ID: 1015697

English Heritage Legacy ID: 15453

County: Isles of Scilly

Civil Parish: St. Agnes

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 on the western and southern
coastal margins of Castella Down, on the western promontory of St Agnes in the
Isles of Scilly. On the south west coast of the Down the monument includes a
defensive bank called a breastwork, erected during the English Civil War. Near
the breastwork, the monument also includes the post-medieval Troy Town Maze
laid out on the coastal slope.
The prehistoric field system survives as a series of walls and banks which
subdivide the western and southern coastal periphery of Castella Down. Its
walling is generally visible as a line of boulders spaced at intervals along
the wall course; the boulders are frequently edge-set, commonly 0.3m-0.5m high
but occasionally up to 0.8m high. Where present surface vegetation and blown
sand deposits permit, the boulders can be seen to rise from slight rubble
banks, up to 1.5m wide and 0.3m high, with traces of small facing slabs along
each side visible in at least one location. Where their courses roughly follow
the contour, the walls become pronounced earthen banks called lynchets, up to
1m high on their downslope side, created by soil movement against and from the
boundary due to the early cultivation on the slope. The pattern of walling
shows the surviving upper parts of a regular field system, whose surviving
plot walls meet at approximate right angles. The dominant axis of the field
system is strongly influenced by, and changes with, the aspect of the
groundslope, while the actual positioning of several boundaries clearly
relates to the incorporation of prominent natural outcrops and large boulders
as wall terminals.
Reflecting these influences, the western periphery of the Down is subdivided
by at least five walls running directly downslope on a north east-south west
axis: three form major divisions, 90m-115m apart, extending down from 55m to
70m behind the present coastal edge; the northern and southern each terminate
on large outcrops. The other two downslope walls are 40m apart and rise to
only 10m-15m from the coastline, forming the sides of a single plot whose
south east wall and slightly lynchetted upper bank abut the natural outcrop
called the Carns of Castella at the plot's eastern corner. The south east wall
of this plot has also been traced as a boulder line across the inter-tidal
zone for at least 30m beyond the present coastal edge, reflecting the field
system's submergence since the prehistoric period.
A further field wall also extends WNW from the inland end of the northernmost
major division on the west of the Down, reflecting the change to a north west
facing slope and forming a survival of the prehistoric subdivision of that
slope whose area is now occupied by post-medieval enclosure.
In the west of the Down's southern periphery, two walls run downslope, north
west-south east and 20m apart, the eastern only visible at the coastal
cliff. Behind the centre and east of the southern periphery, two large
adjoining plots are visible. The inland edge of the eastern plot is marked by
a high, slightly curving lynchet running WNW from the Pink Carn outcrop; at
the west the lynchet meets a wall extending NNE from the Beat Carn outcrop,
giving a plot 55m-60m wide with sides defined almost entirely by the rocky
scarps of the parallel Pink Carn and Beat Carn outcrops. The wall north of
Beat Carn continues 15m beyond its junction with the lynchet to define the
east side of the adjoining plot. At the north, the wall turns west across a
modern field, defining the inland side of the prehistoric plot. Here its
course is visible as the lynchetted line of a recently-removed subdivision of
the modern field. The south wall of the adjoining modern field extends beyond
this towards a natural outcrop. The west side of the prehistoric plot is
considered to correspond with the field wall running SSW as the west side of
the modern field almost reaches the coast beside Beat Carn, giving the
prehistoric plot a width of 50m-58m. Within the north east corner of the
modern field which occupies much of that plot is a small ruined two-roomed
building probably of 19th century date.
The post-medieval breastwork is visible near the southern end of the Down's
western coast. It survives as a slight bank averaging 1.1m wide and 0.15m
high, with occasional small slabs projecting through the turf cover. The
southern end of the bank commences at the coastal edge, beside the northern
end of a group of large massive outcrops marking the south western corner of
the Down. From there the bank extends 10m east and then turns north at
right-angles, extending for a further 35m, gradually converging on the coastal
cliff to the point where the cliff eventually truncates it. In common with the
other breastworks erected in Scilly during the Civil War (AD 1642-1651), this
bank would give cover for defensive forces along the coast fronting one of the
deep water channels into the archipelago, in this case Smith Sound, providing
an entry from the south and east which avoided passing close to the heavily
defended Garrison promontory on St Mary's.
Several metres upslope from the breastwork is a large maze, known as the Troy
Town Maze, laid out on the grassy slope within the prehistoric field system.
Its paths, worn bare and slightly hollowed by visitors, are defined by single
rows of beach cobbles bedded into the surface turf and rising 0.1m-0.2m high.
Overall the maze is ovoid, measuring approximately 5.5m north-south by 5m
east-west; it has a labyrinthine pattern, with an entrance on the eastern,
uphill, side, from which near-concentric curving paths take the visitor
alternately from one side to the other, and towards the centre, then to the
periphery, and finally back to the centre again. Local tradition maintains
that the maze was originally laid out in 1729 by Amor Clarke, a keeper of the
St Agnes lighthouse. Although known to have undergone a rebuild on at least
one recent occasion, its present pattern matches that clearly shown on an 1885
photograph of the maze. Its `Troy Town' title preserves the name by which
mazes were commonly known throughout England in the earlier post-medieval
period when they formed a widespread recreational feature; of the few
surviving early examples, no other pre-20th century British mazes share the
cobble-defined construction of this type of pattern, though the Troy Town Maze
itself has inspired many modern copies. The name of this maze has also become
transferred to `Troy Town Farm' which occupies much of the promontory within
and beyond this monument.
Beyond this monument, further prehistoric field system and settlement sites
survive from 350m to the ESE and from 750m to the north east on northern
Wingletang Down and at Higher Town and Porth Killier respectively; a very
large prehistoric cairn cemetery also extends across much of Wingletang Down,
and further prehistoric settlement and funerary remains occur widely across
the neighbouring island of Gugh to the east.
All modern post-and-wire fences, gates and their fittings are excluded from
the scheduling but the ground beneath them, and all field walls, are included.

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.

The regular field system on Castella Down survives well, clearly displaying
the character of the prehistoric land division and the strong influences upon
it of the natural topography. Despite truncation of its lower edges by rising
sea levels, the field system contains a sufficient range of elements to
determine its nature and extent, assisting our understanding of prehistoric
land use over a far wider area than the confines of the monument. In this
broader role, the field system complements the other surviving and broadly
contemporary settlement remains on St Agnes and Gugh, together with the large
cairn cemeteries on Wingletang Down and Gugh, to provide an unusually
extensive view of prehistoric land use in this area.
The Civil War breastwork in this monument shows well the strategic location
where that type of defence was deployed; the surviving pattern of Civil War
breastworks and batteries on the Isles of Scilly, of which this breastwork
forms an integral part, forms one of the most complete and best preserved
defensive systems of that period. Also within the monument the Troy Town Maze
preserves its original pattern, confirmed by 19th century photographic
evidence, despite some rebuilding. This maze provides a good example of a
once-popular and now scarce form of local pastime, and unusually retains the
traditional name applied to mazes. Its combination of labyrinthine pattern
and mode of construction is unique in England among surviving pre-20th century
mazes. It also shows well the significant place that mazes occupy in popular
consciousness, not only giving rise to local traditions and place-names but
more recently inspiring many copies created in several parts of Scilly by
modern visitors.

Source: Historic England


Books and journals
Arlott, J, Island Camera, (1983)
Grigson, G, The Scilly Isles, (1977)
Grigson, G, The Scilly Isles, (1977)
Mumford, C, Portrait of the Isles of Scilly, (1970)
Ratcliffe, J, Lighting up the Past in Scilly, (1991)
Title: 1:2500 Ordnance Survey Map; SV 8707
Source Date: 1980

Title: 1:2500 Ordnance Survey Maps; SV 8707 & SV 8708
Source Date: 1980

Title: 1:25000 Ordnance Survey Map; Isles of Scilly: Outdoor Leisure Map 25
Source Date: 1992

Waters, A & Ratcliffe, J/CAU, AM 107 for Scilly SMR entry PRN 7002, (1989)
Waters, A/CAU, AM 107 for Scilly SMR entry PRN 7000, (1988)
Waters, A/CAU, AM 107 for Scilly SMR entry PRN 7001, (1988)

Source: Historic England

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