An Iron Age religious site and associated enclosures on Gallows Hill, Thetford, immediately to the north of Fison Way industrial estate


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Scheduled Monument
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Ordnance survey map of An Iron Age religious site and associated enclosures on Gallows Hill, Thetford, immediately to the north of Fison Way industrial estate
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The building or site itself may lie within the boundary of more than one authority.

Breckland (District Authority)
National Grid Reference:
TL 86707 85061

Reasons for Designation

The foci of Iron Age religious practice lay in the natural world, in rivers, wells, lakes and sacred groves, as well as in defined sacred enclosures, temples and shrines. A small number of the latter have been identified, most readily recognized where they have been found to precede a Romano-Celtic temple, that is, in the majority of cases. A minority are located within hillfort or village settlements. Iron Age temples or shrines vary in size between 2.5m and 13m. Almost invariably of post built timber construction, they may be round or square, generally enclosing a single space, but more rarely containing an inner chamber and outer ambulatory. The entrance is to the east, and in the majority of cases they are surrounded by a defined enclosure, with a boundary formed by a ditch or palisade, or by an undefined open space: where the shrine was succeeded by a Romano-Celtic temple, both boundary and temple would usually be reconstructed or replaced in stone. The open enclosure would probably have been the place where ceremonies were conducted, with the shrine or temple, often too small for congregational worship, the object of offerings and individual devotion. About half have produced votive offerings of a general nature, that is, not identifiable with a specific deity. These consist mainly of brooches, coins and miniature weapons, as well as animal bones, presumed to be the remains of sacrifices. The earliest of these structures associated with ritual and religious practice can be dated to the 4th century BC, the latest to the mid 1st century AD. The distribution of these sites is through the south and east of England, with none known north of the south midlands, or in Devon and Cornwall. In view of their rarity and their potential to contribute to an understanding of Iron Age religious belief and practice, and to the transition from Iron Age to Roman culture, all those with surviving archaeological potential should be considered to be of national importance. The Late Iron Age site on Gallows Hill is one of the most significant in the country. The sacred associations of the site are at least as old as the Bronze Age; we know that activity intensified through the Iron Age into the early Romano-British period, with a final expression in the 3rd and 4th centuries AD. The site has much to tell us about the changes in cultural and religious forms during that time. The main enclosures and the structures they contain may be interpreted as having a sacred function, and share features in common with those outlined above. The site was destroyed in the early Roman period, before it could be allowed to develop into a Romano-Celtic temple, and is without a known parallel. When religious or ritual activity returned to the hill top its focus was a building constructed to the south of the monument, now under the Travenol factory. Coins associated with this period of activity were found in an area to the west of the enclosures and therefore this area is included in the scheduling. The successive double ditched enclosures were produced by complex political and social developments in the early years of the Roman occupation, the period of Icenian clientship and its violent end. The resources needed for both Phase II and Phase III structures would have been considerable, and indicate are indicative both of the power required to control such a project, and of the significance of its religious and ceremonial purpose. The grandeur of such a construction demonstrates the benefits gained from the client relationship by the Icenian elite, and also its risks; it seems probable that it was resistance to Roman control that brought about its destruction as an act of reprisal, the removal of a symbolic focus of Icenian power reinforcing the suppression of revolt. Although all visible features were planned in the course of excavation, only 5% were actually excavated. The excavation report acknowledges that the sample was inadequate, the quality of excavation and supervision at times poor, and that the area examined was too limited to provide context. Most of the features within the excavated area therefore remain intact, and the site still has great potential; future techniques and methods of analysis may reveal more than can be gleaned at present.


The monument includes the buried remains of three phases of a ritual or ceremonial enclosure dating to the Late Iron Age; also associated with these are further enclosures, ring ditches and other features. Gallows Hill lies to the north of and 35m above Thetford and the confluence of the Rivers Thet and Little Ouse. The monument is centrally placed on the broad, flat plateau that forms the top of the hill, the soils of which consist of blown sands and outwash gravels covered by a thin layer of topsoil. The site is crossed from north to south by the Icknield Way, and its location commands a strategic position overlooking the river crossings, with broad views on all sides, particularly to the south and west. It lay within the territory occupied in the Iron Age by the tribal group known as the Iceni. The three enclosure ditches were first identified from aerial photographs taken in 1973, but it was not until 1980 that their significance was recognized, following discoveries made the previous year. In 1979 the removal of topsoil in advance of construction of the Travenol factory to the south of the monument revealed a complex of gullies, pits and ditches. Tiles and brick were also found, concentrated on 30 square metres in the north west corner of the factory site but spread over a wider area, where metal detectorists attracted to the site also found thousands of late Roman coins. The most spectacular find, a hoard of gold jewelry and silver spoons, the majority engraved with dedications to the god Faunus, was not revealed by the finder until the following year. This hoard was named the Thetford Treasure, and is now in the British Museum. The nature of the hoard, and the finds from the wider area, suggested that the site revealed in the course of construction of the factory was a Romano-Celtic temple. This interpretation aroused greater interest in the enclosures immediately to the north, which had by chance been photographed again in the same year. As the whole of this area had been designated for further development of the Fison Way industrial estate it was decided to conduct a programme of investigation, including survey and excavation. Over the next two years the whole of the area containing the triple ditched enclosure revealed by aerial photography was stripped of topsoil, except for the south west corner; all visible features were planned and about 5% of the whole was excavated. The excavation demonstrated that apart from some prehistoric activity, most features could be divided between three phases of the site's development. The first can be assigned to a period before the Roman invasion of AD 43, the second and third to the decades following, when the Iceni had become a client kingdom of the invading Romans. This phase of occupation ended in the early AD 60s, and the site remained unoccupied until the 3rd and 4th centuries. The sudden abandonment of a site of this scale and significance around the time of Boudicca's revolt of AD 60 and its suppression strongly suggests a connection between the two events. The earliest structural remains consist of a late Neolithic/Early Bronze Age pit, and five Bronze Age cremations. In this period the landscape was cleared of its tree cover, and by the Iron Age the hill top had already been colonized by heath. This was the setting for the first main phase of pre-Roman development, represented by a series of rectangular and trapezoidal enclosures, ditches and two groups of pits. Of the three main enclosures, the most intact, measuring approximately 60m x 60m, lies immediately to the north of the later Phase II enclosure; phosphate analysis indicates that their use was not agricultural. Pottery associated with this phase suggests that its beginnings lay sometime between the 4th and 2nd centuries BC. The second phase, datable to the mid AD 40s, saw a dramatic increase in both the scale and intensity of occupation at the site. A substantial double ditched enclosure was constructed, the outer ditches describing an area about 100m square, with an entrance in the centre of its east side: between the inner and outer ditch there seems to have been a slight rampart, with a fence embedded in it. Access to the centre of the monument was controlled through parallel fences flanking the entrance, and between two substantial posts that lay just inside the ends of the outer ditch. Directly opposite the entrance, but slightly to the west of centre, lay a circular building represented by an eaves drip gully measuring 13m in diameter, within which were an outer circle of wall posts and an inner of roof posts: the entrance was to the east. A secondary rectangular enclosure, with a separate entrance also in its east side, was later added to the south of the double ditched enclosure. Further enclosures to the west are both earlier than and contemporary with the double ditched enclosure. Clustered around it to the north and north west are a group of enclosures and ring ditches, some of which contain rectangular, body sized features which have been interpreted as graves, despite the fact that no organic matter, including bone, survives in these soils. Evidence of metalworking, crucibles for casting in bronze, and pellet moulds for the production of silver blanks for coins, is also associated with this phase. Sometime in the AD 50s, this enclosure was swept away and replaced with a much larger double ditched construction: this is Phase III. This was done by backfilling the inner ditch and the east arm of the outer ditch and extending this side of the enclosure eastwards to form a rectangle. A new outer ditch was then dug to enclose the whole in a rectangle measuring about 220m x 160m. Not only was it enlarged to enclose over twice the original area, its impact was enhanced by the addition of a thicket of fences, up to nine deep, which filled the space between the inner and outer ditches: this has been described as 'an artificial oak grove', a reference to contemporary descriptions of Celtic religious practice taking place within sacred groves or woodland clearings. The approach from the east was along a fenced avenue and through a gateway constructed of two pairs of substantial posts set between the inner rampart and inner ditch. The avenue extends beyond the excavated area: it can be seen on aerial photographs continuing into the field to the east, where there are also smaller enclosure on the same alignment. Contained within the double ditched enclosure were five circular structures. The building from Phase II, modified to form a slight elipse with entrances to east and west, was centrally placed between two similar buildings. To the east of these were two smaller circular structures, the remains of which are more ephemeral. There is no evidence that any of these structures had a domestic function. This third phase of enclosures was brief. Early in the AD 60s all upstanding structures were systematically demolished, with posts either dug out or removed by rocking to and fro, distorting post holes from round to oval. For the next two hundred years the site remained unoccupied. The ditches of the Phase III enclosure were still partially open at this date, and remained so into the 4th century and beyond. Further features datable to this period were found in a trench lying south of the main excavation. (Its location is to the north-east of the factory and immediately to the north of the assumed find spot of the Thetford Treasure). These include five post holes and two gullies, interpreted as the fragment of an aisled building. The scheduling is intended to provide protection for both the enclosures and features within the excavated area and also those features and areas of archaeological activity immediately to the north, east and west identified by aerial photographs, metal detecting and geophysical survey. It includes the greater part of the field which contains the enclosures as well as that part of the field to the east which contains the avenue and small enclosure identified from aerial photographs. All fences, gate posts and boundary markers are excluded from the scheduling, although the ground around and beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.


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This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

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