The excavation and survey of prehistoric enclosures at Blackshouse Burn, Lanarkshire

Limited excavations were carried out in 1985-6 on a large, subcircular enclosure and a smaller adjacent one, built on the edge of an ancient bog, on Pettinain Hill in Lanarkshire. These investigations established that the larger monument had been built by erecting a double row of timber posts and piling a stony bank between the two rows; the preserved, waterlogged stumps of oak posts were found in post-holes on either side of the bank. The bank was later elaborated, with stones pitched around the standing posts and, in a final stage, it was capped once the posts had decayed. Excavations on the bank defining the much smaller, adjacent enclosure, built just within the bog, found it had been built by digging holes in the peat and building a stone structure above. An oak post from the large enclosure was dated to 4035 + 55 BP (2697-2453 cal BC). The authors suggest the large monument had its origins in an early Neolithic tradition of transhumance and that its builders were drawn and held to the upland basin by the presence of water there. The excavation was directed by Peter Hill; the project has been funded throughout by Historic Scotland and its predecessor department (SDD/HBM