Multiple enclosure fort 300m north east of Tretherres


Heritage Category: Scheduled Monument

List Entry Number: 1020798

Date first listed: 03-Sep-2002


Ordnance survey map of Multiple enclosure fort 300m north east of Tretherres
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The building or site itself may lie within the boundary of more than one authority.

District: Cornwall (Unitary Authority)

Parish: St. Allen

National Grid Reference: SW 81971 50324


Legacy Record - This information may be included in the List Entry Details.

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.


Legacy Record - This information may be included in the List Entry 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.


The contents of this record have been generated from a legacy data system.

Legacy System number: 32966

Legacy System: RSM


Books and journals
Padel, O J, Cornish placename elements, (1985), 50, 57
Dyer, C, Cornwall Mapping Project, (1999)
MS at RIC library, Truro, Henderson, C, Parochial Antiquities, Parochial Antiquities, (1917)
PRN 32035, Dyer, C, Cornwall SMR, (1999)
SW 85 SW 22, King, AN, Ordnance Survey Index Card, (1970)
Title: Ordnance Survey 1:2500 Map Source Date: 1880 Author: Publisher: Surveyor:
Title: Ordnance Survey 1:2500 Map Source Date: 1907 Author: Publisher: Surveyor:
Title: St Allen Tithe Apportionment Source Date: 1841 Author: Publisher: Surveyor: 756-758
Title: St Allen Tithe Apportionment Source Date: 1841 Author: Publisher: Surveyor: 757

End of official listing