ORCA was commissioned by Historic Scotland to undertake an archaeological evaluation of a suspected prehistoric funerary monument on the eastern slopes of Wideford Hill, St Ola, Orkney. The site first presented itself as a subterranean cavity caused by the apparent collapse of a capstone under the weight of a tractor whilst ploughing: the first time that the field had been cultivated since the 1960s. Initial inspection of the cavity revealed the structure to be lined with coursed masonry. Both the lack of associated surface material and the 'quiet' response from the geophysical surveys carried out around the cavity, and the relatively high elevation of the site at approximately 120 mAOD, made the interpretation of a chambered tomb or a cist likely. An intrusive evaluation of the site carried out over three days in June 2009 by ORCA revealed a single cist-like structure with a rock-cut base and sides of drystone masonry. The fill comprised only a dark brown clay and the cist was fully emptied. A field drain, probably of post-medieval date, was revealed running alongside the cist. It is suggested the excavation of this drain may have been responsible for the initial weakening of the capstone which allowed it to be dislodged during ploughing. Following the approval of additional funding by Historic Scotland, additional fieldwork took place involving the recording of the elevations of the cist, the removal of the built elements of the structure and the dismantling of the cist. No artefacts or human remains were recovered from within the structure. Much of what appeared to be coursed masonry actually turned out to be the horizontal bedding planes of the natural flagstone bedrock. It appears that the original builders exploited and mimicked the natural characteristics of the local geology in the construction of the cist, in order to manipulate the categories of 'natural' and 'built'.
Antonia Thomas (Thu,) studied this question.