SDO17205 - Ancient Monuments Laboratory Geophysics Section. Report on Magnetometer Survey: lake Farm 1980

'This year, the survey was further extended to include a large area to the north-east of the farm buildings. This achieved some idea of the overall pattern and dimensions involved. Evidence up to this point suggested the possibility of fort defences running roughly WNW – ESE beneath the farm, and then on the eastern side at some point turning northwards, forming the south-eastern corner of the fort. Almost the entire area covered by this year’s survey contains a multitude of features such as were detected in the adjacent area in 1976. A large number of very faint anomalies that are too weak to be convincingly delimited have had to be ignored, suggesting that the picture is inevitably partial. Perhaps the most significant aspect of the pattern of anomalies to emerge is the ditch arrangement that probably represents at least a part of the fort defences. Two alignments can be traced. Although neither of these ditches can be seen individually to turn a right-angle towards the farm, there are other broader anomalies related to their alignment, although perhaps of a different phase, whose general curvature suggests a putative south-eastern corner. Ditches to the west of the main N – S alignment maintain a rough rectilinearity and presumably represent fragments of the internal structure of the fort. In the southern half of the survey area there is a profusion of very strong anomalies occurring. Augering of several of these confirms their industrial nature and it is very likely that several of them are kilns. Magnetometer surveying at Lake Farm has at the least proved the very large extent of the site and something of the density and distribution of features to be found in the areas covered. The remains of a rectilinear ditch system has been indicated and at the eastern edge of the survey a ditched boundary exists. There is evidence that the most obtrusive anomalies may be industrial in origin and in part belong to a late phase in the site’s history. A destructive phase, particularly if involving severe burning, could also have contributed to magnetic enhancement. That some of the ditches may represent independent enclosures or field boundaries ought to be considered. With the exception of the suspected south-eastern corner, a possible roadway and possibly related rectilinear ditches, no specific features of the fort can be proven from the survey alone and its exact dimensions must remain open to debate. '