Monument record MHG54322 - Round cairn with cist, Dounreay

This cairn was identified during a walkover survey in 2005. It comprised a large circular mound approximately 10m in diameter and standing to a maximum preserved height of 0.65m. It was fully excavated in 2010 in advance of construction of the new Dounreay Low Level Waste Facilities. The stone cairn [102] was formed of poorly sorted interleaving layers of large flagstones, predominantly of the local Dounreay Siltstone and most likely sourced from the immediate vicinity where this stone is abundantly available. A single small flint flake was recovered from the sandy clay matrix between the stones. The flake is of honey brown flint and undiagnostic, but is likely to be prehistoric and probably dating to no later than the end of the Bronze Age. On the southern side of the cairn the arrangement of stones seemed to form a distinct kerb along its outer edge. The kerb was less distinct on the north and west sides. There was a suggestion of horns on the north-western side of the cairn but they did not seem to form a coherent or regular shape. Below the cairn was a single stone-lined cist [113] located slightly off-centre that cut into the natural clay/bedrock. It was only when the cist was discovered that it became apparent that the cairn had previously been disturbed. Four large upright stone slabs forming a large almost trapezoidal cist aligned roughly east-west with a flagstone capstone and base. The internal dimensions of the cist were 1.10m E-W by 0.66m N-S at the east end and 0.44m at the west end. The capstone had been broken in two and was set north-south across the west end of the cist showing that the cist must have been disturbed in antiquity. Although the primary fill seemed relatively undisturbed no human remains or artefacts were recovered during the excavation. Two distinct layers [103] and [104] (possibly also [105]) at the base of the cairn were interpreted as buried soil deposits. These were clearly associated with the cist and probably formed an important part in a series of events that culminated in the construction of a large cairn. Charcoal was recovered from the lower of the silt layers. Charcoal was also recovered from a sandy clay layer recorded over the outer edges of the cairn and possibly relating to the final phase of the cairn construction. No secure date for the cairn has yet been identified but it is thought that the cairn is similar to many other cairns that have been dated to the Bronze Age. <1>

Interpretative posters have been produced by Headland Archaeology Ltd for display at the site. <2>