County: Offaly Site name: CORHILL BOG, Lisdermot/Straduff
Sites and Monuments Record No.: N/A Licence number: 00E0400
Author: Ellen OCarroll, ADS Ltd.
Site type: Road - gravel/stone trackway - peatland
Period/Dating: Medieval (AD 400-AD 1600)
ITM: E 613427m, N 727868m
Latitude, Longitude (decimal degrees): 53.300935, -7.798552
Excavations were carried out in Corhill Bog, Co. Offaly, as part of the Bord na Móna Archaeological Mitigation Project. These excavations were undertaken to resolve known archaeological sites so that Bord na Móna could resume peat production in areas that had been cleared of archaeology. The field season ran from June to August 2000.
This site comprised a gravel-and-wood trackway, which could be traced across the width of Corhill Bog for over 400m. The trackway was located on a natural rise in the peat bog. In total, 15m of this trackway was excavated at four different locations. The unexcavated areas were recorded at intervals along its length, and a comprehensive record of the stratigraphy of the trackway was obtained. Excavation revealed that the trackway varied in composition along its length, as did the level of preservation. In one cutting it was composed of brushwood underlain by gravel; in another it was composed of just brushwood; and at other locations the trackway was composed of just gravel. It measured up to 1.8m in width, and its depth varied depending on materials used in the construction. The wood layer for the most part overlay the gravel and consisted of gnarly brushwood, twigs, bark and layers of tree leaves. In one of the cuttings the wood was arranged transversely across the width of the site and was delineated by larger roundwoods that ran longitudinally. In other cuttings there does not appear to have been any particular arrangement to the wood. The gravel consisted of sub-angular, small, coarse pebbles, some of which had degraded to a coarse sand. The largest pebbles measured 45mm by 20mm, and the smallest 5mm by 5mm.
A small number of flagstones were excavated along the length of the trackway. They were probably laid down to add further stability to the walking surface. This trackway may have been constructed to facilitate safe crossing across the bog as well as providing access to and from a series of wooden platform structures (see Excavations 2000, Nos 819–26) excavated at the southern end of this trackway.
As the site was located c. 1m over the plank trackway described in No 829 Excavations 2000, dated to AD 626, an approximate calculation of the date for the gravel and wood trackway would be around the 15th or 16th century AD.
Windsor House, 11 Fairview Strand, Fairview, Dublin 3
