Walkover Survey at Borehole Decommissioning Works, Stonehenge, Wiltshire. Archaeological Walkover Survey

The walkover survey identified 77 borehole locations which were recorded using a Leica GNSS connected to Leica's SmartNet service. All survey data is recorded in OS National Grid coordinates and heights above OD (Newlyn), as defined by OSTN15and OSGM15, with a three-dimensional accuracy of at least 50 mm. A full photographic record was made using digital cameras equipped with an image sensor of not less than 10 megapixels. Digital images have been subject to managed quality control and curation processes, which has embedded appropriate metadata within the image and will ensure long term accessibility of the image set. Boreholes were located both within and without the Stonehenge, Avebury and Associated Sites World Heritage Site (NHLE 1000097) with all but two in the immediate environs of known archaeological remains dating from the Mesolithic (settlement at Blickmead) through to the modern day period (World War I features such as aerodrome and military railway). Previous archaeological mitigation works have been undertaken in the location(s) and surroundings of many of the ground monitoring installations. The results of such indicated a general paucity of archaeological remains within the borehole locations with a single ditch and lynchet identified during the two phases of previous archaeological mitigation undertaken in the locale of the boreholes. Following the identification of the boreholes within proximity to known archaeological remains, such as barrows, which are of intrinsic value to the Stonehenge, Avebury and Associated Sites World Heritage Site (NHLE 1000097), it is recommended that an archaeological watching brief be undertaken during the decommissioning works on the borehole locations where earlier mitigation was not undertaken. Given the archaeological sensitivity of the area and the proximity of the boreholes to barrow monuments and early prehistoric settlement (i.e. Blickmead) such an approach is considered commensurate with the impact of the proposed removal.