Borough Hill Enclosure, Sawston, Cambridgeshire: An Archaeological Watching Brief

Between the 5th and 7th March 1997 the Archaeological Filed Unit of Cambridgeshire County Council completed a watching brief on behalf of Spicers Ltd, Sawston, during the digging of a pipeline for a high voltage cable. The route crossed the perimeters and centre of an iron Age Hillfort (Borough Hill) and was recorded in detail between TL 4707/4957 – 4709/4951. The work demonstrated the survival of the base of the outer rampart sealing buried soil. It also confirmed the presence of the outer and inner ditches, previously identified during a geophysical survey and air photographs. Only the upper fills of the ditches were examined due to the limited nature of the disturbance. Of particular importance was the recovery of a small assemblage of pottery which has been provisionally identified as early Anglo-Saxon. An additional linear was found truncating the southern edge of the outer bank. This feature was also identified during a geophysical survey and appears to follow the outer defences of the fort. This later ditch would appear to provide evidence for a later phase of defences. Within the enclosure several internal features were recorded which have been identified as either drainage gullies or pits and which could be associated with contemporary settlement. Additional features were recorded probably of more recent origin and possibly associated with ‘modern’ landscaping activities. All the work to date indicates that the banks have been spread out into and over the ditches and the interior of the site, although at present it is difficult to establish whether this is the result of a deliberate slighting or as a result of ploughing. This latest phase of archaeological investigations, although very limited, has proved very informative enabling clarification of the nature of the defences and allowing comparisons to be made with other hillforts within the region. However, given the limited nature of the investigations so far, further archaeological work would be necessary to understand the history and development of the fort more fully.