Reasons for Designation
Multiple enclosure forts comprise an inner and one or more outer enclosed
areas, together measuring up to c.10ha, and defined by sub-circular or sub-
rectangular earthworks spaced at intervals which exceed 15m; the inner
enclosure is usually entirely surrounded by a bank and ditch. The forts date
mainly to the Late Iron Age (350 BC-c.AD 50) and in England usually occur in
the south west. Most are sited on hillslopes overlooked by higher ground near
a water supply, and many were apparently used for periods of up to 250 years.
The outer enclosures of the forts are usually interpreted as areas set aside
for the containment of livestock, whilst the inner enclosures are generally
thought to have been the focus of occupation.
The earthworks usually include a bank with an outer V-shaped ditch 1m-3m deep.
Entrances are generally single gaps through each line of defence, often
aligned to create a passage from the outer to the inner enclosure, although
there are a few examples where entrances through successive earthworks are not
in alignment. Occasionally the interval between the gaps is marked by inturned
ramparts or low banks and ditches, while the outer entrance may be screened by
a short length of earthwork. Excavations within the inner enclosures have
revealed a range of buildings and structures, including circular structures,
hearths, ovens and cobbled surfaces as well as occasional small pits and large
depressions which may have functioned as watering holes.
Multiple enclosure forts are relatively rare with only around 75 examples
recorded in England, mostly in Devon and Cornwall. Outside these counties
their distribution becomes increasingly scattered and the form and
construction methods more varied. They are important for the study of
settlement and stock management in the later prehistoric period, and most
well-preserved examples will be identified as being of national importance.
Despite partial reduction and modification of its enclosing banks, and
filling or silting of its external ditch, the multiple enclosure fort 300m
north east of Tretherres survives comparatively well. The underlying old
land surface, and remains of any structures or other deposits associated
with this and with the upstanding earthworks and buried ditches, will also
survive. The evidence for an adjoining external structure is unusual, and
both this and the association with other enclosures nearby could
contribute to our understanding of the social and economic organisation of
the farming landscape of this region in the later prehistoric period.
Details
The scheduling includes a prehistoric multiple enclosure fort lying on the
summit and south shoulder of a rise on a ridge south west of St Allen. The
fort is irregular in overall plan, having a roughly D-shaped outer
enclosure, an oval inner enclosure near the centre of this, and a
sub-circular structure beyond the fort on the south east side. The fort
lies within a field system of medieval origin. This has been levelled by
cultivation, is beyond the prehistoric remains and is not included in the
scheduling. The monument measures up to approximately 200m north
west-south east by 150m south west-north east. It is one of several
comparable enclosures surviving in this area. The outer enclosure has a
rampart of earth and stone, with an external ditch. Around the south and
west sides the rampart has been spread by ploughing, but can be seen both
on aerial photographs, and on the ground as a scarp 10m-15m wide and up to
0.6m high. On the north and north east sides it is considered to have been
modified to form later field boundary banks. Aerial photographs record a
buried outer ditch on the west side. Comparison with other forts
indicates that the ditch extends around the remainder of the outer
rampart.
The inner enclosure, and the feature adjoining the fort on the south east
side, are not upstanding, but are shown on aerial photographs. The inner
enclosure has a rampart, recorded on the photographs around the north west
and south east sides; as with other comparable enclosures, this will have
a buried external ditch. The enclosure's internal dimensions are
approximately 40m north west-south east by 30m south west-north east.
The feature on the south east side measures around 15m across and is
defined by a ring ditch. This is considered to be a foundation trench for
walling surrounding a round house or other prehistoric structure
associated with the fort. A gap in the ditch on the south east side marks
its entrance.
The elements of a field system of medieval origin lie to the south west
and north east of the multiple enclosure fort. On the south west side, a
long, narrow, slightly sinuous field, of the type formed by enclosing
strips of medieval open field, runs east-west over the fort's outer
enclosure. It is marked on old maps, and its north boundary survives as a
hedge bank. A similar strip runs north-south on the north east side of the
fort. Its long sides are defined by buried ditches, shown on aerial
photographs, and its east side is also visible on the ground as the field
boundary bank on the north east side of the fort, formed from its outer
rampart.
The modern fencing is excluded from the scheduling, although the ground
beneath it is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
