Site of conjectured Roman amphitheatre, reinterpreted as an octagonal temple and precinct, Borough Field, Great Chesterford (EHER 4936)

In Borough Field, between the Roman town and river, is a large circular ditched enclosure measuring approximately 30m in diameter, and initially interpreted as a Roman amphitheatre. It is recorded as a cropmark in EHER 4935. It was surveyed using geophysics in 1996 and the survey revealed a break in the ditch and a small pitch at the centre of the feature, suggesting it may instead be a prehistoric barrow. A further geophysical survey in 2003 was able to shows that the feature was in fact composed of a series of short straight lengths of ditch forming an octagonal structure or enclosure measuring 31m across and enclosing an area of 760 square metres. The octagonal shape of the structure is paralleled at several other Roman sites, such as at Chelmsford (EHER 5865) and Elms Farm, Heybridge (EHER 18774) all of which have been interpreted as temples. Whilst the Great Chesterford example is considerably larger than its local counterparts, it draws parallels with continental examples such as at Le Hérapel, Moselle, and lends itself well to interpretation as an octagonal temple.

In Borough Field, between the Roman town and river, a supposed Roman amphitheatre. Corn grew there in a wide circle 8yds wide, enclosing a space 100yds in diameter. It is depicted on aerial photographs as a pennanular cropmark - it's unlikely to be an ampitheatre as it is within the Roman town. On the ground can be seen a scatter of large flints and Roman tile. The scatter is 30 x 20m. There are no surface features to give a more precise identification. <1> <2> January 1977. Field survey. The cropmark visible on the APs as a circle 30.0m diameter, is seen on the ground as a scatter of large flints and Roman tile. The scatter measures 30.0 m by 20.0 m and occurs in flat arable land. No surface features are visible which could identify the scatter other than as a round Roman building. Surveyed at 1:2500. <2> <3> In the field known as Borough Field (which lies between the Roman Town and the river) "in which is supposed to have been an amphitheatre, the corn growing there in a circle eight yds wide, including a space of a hundred yds diameter". <4> "An amphitheatre has ben conjectured, a little rashly from foundation marks in the fields near the river". <5> A penannular crop mark visible at TL 5020 4307 (unlikely to be an amphitheatre as it falls within the Roman Town and Camp). <6 The amphitheatre may be the ring ditch identified from air photographs (see EHER 4935). Borough field as given on the OS card is a large area between the River Cam and the Newmarket Road enclosing the whole of the Roman town. The grid reference given is only an approximation for the possible site given the statement 'between Roman town and river'. <7> 1996. Geophysical survey. A geophysical survey of three hectares of land at the centre of the Roman settlement and to investigate a series of cropmarks (EHER 4935) identified substantial archaeological remains indicative of a fort (see EHER 4942) and later town development (see EHER 4915). The large circular ditched enclosure showed up as a notable anomaly approximately 30m in diameter. There is a possible break in the ditch on the northern side and a small pit directly at its centre. Its relationship with other features of the Roman town is unclear. Although the majority of other anomalies respect its boundaries there is some indication of disturbance to its southern and south western edge which may represent back filling in antiquity. The size of the ditch and presence of the central pit could be interpreted as evidence of a barrow. Its existence would obstruct later Roman settlement. <8> The circular enclosure and internal pit are plotted on the NMP cropmark plot. On its west side it abuts a three-sided rectangular enclosure. <9> 2002. Geophysical survey. The geophysical survey of the town identified a possible octagonal temple. This feature had previously been observed by Braybrooke and Mr Shepherd and interpreted as a possible amphitheatre. Aerial photography had identified a circular feature in this area which was tentatively interpreted as a possible round barrow. However, the geophysical survey has demonstrated that it is actually composed of a series of short straight lengths of ditch forming an octagonal structure or enclosure measuring 31m across and enclosing an area of 760 square metres. To the east of this was attached a wedge-shaped area (54m by 52m at its widest point) bordered by the main north road (EHER 4744), to the east and the market place (EHER X) to the south. A number of large pit-like features can be observed within this area. The octagonal shape of the structure is paralleled at several other Roman sites, all of which have been interpreted as temples. These include the octagonal temple at Chelmsford (EHER 5865); the triple concentric structure at Nettleton, Lincolnshire; the fragments of an octagonal temple at Caerwent 2, Monmouthshire; and the octagonal temples at Pagans Hill, Somerset, and Weycock Hill, Berkshire; this last, incidentally, was excavated by Braybrooke. The Great Chesterford octagonal structure is considerably larger than these other examples, but is comparable in size to a number of continental examples, such as the octagonal temple at Le Hérapel, Moselle. Unlike all these other sites, however, the geophysical survey shows no trace of an internal cella, and although there is a faint hint of a central post or pit, it is not of sufficient certainty to plot confidently. Of interest here is the 1847 description of the corn growing thin in a circle approximately 7.28m in diameter. The most likely reason for such a circle is the presence of solid foundations beneath the topsoil, and the geophysical survey method used (magnetic susceptibility) would not necessarily have picked this up. It is not possible, therefore, to be certain as to whether the plan of the monument, as it stands, represents an octagonal unroofed enclosure, possibly with a central post or pit, or a small circular masonry structure, enclosed by a larger octagonal temenos. An intriguing possibility is a link between this octagonal structure and the other known octagonal monument from the town, the Jupiter Column (EHER 83268). The wedge-shaped enclosure to the east of the octagonal structure may be part of the same complex; certainly, comparisons can be made between this feature and the enclosed space associated with the temple at Elms Farm, Heybridge (EHER 18774). A hoard of 198 coins (EHER X)was recorded by Braybrooke as having been discovered in the northern part of the Borough Field; the coins, which dated from AD 37–192, and many of which may never have been in circulation, may represent an offering buried in or near the octagonal structure. <10> <11> <12> Original HER entry merged with NRHE data transfer.