2002:1559 - DERRYARKIN BOG, Bunsallagh/Derryarkin/Derrygreenagh, Offaly

Derryarkin Bog is a Bord na Móna bog that has gone out of milled peat production and was surveyed on behalf of Dúchas as part of the Peatland Survey 2002. Covering an area of 789ha, it lies c. 2km south of Rochfortbridge and is situated west of Bord na Móna’s Drumman Bog and north of Ballybeg Bog. It extends into County Westmeath, but all of the archaeological sites discovered were in County Offaly. A total of 29 sites were recorded, including the find spot of a Late Mesolithic Bann Flake recovered by the Irish Archaeological Wetland Unit in 2000. The remaining sites occurred in two principal concentrations: 23 in the south-western corner of the bog, and five on the eastern fringe. The south-western concentration consists primarily of small deposits of wood and the remains of three linear sites. All of these were in a very degraded state owing to long-term exposure. A flint flake was also recovered from this area. Two of these sites have been radiocarbon dated to 1937–1644 cal. BC and 1686–1414 cal. BC.

The sites to the east consist of similar small deposits of wood and a substantial plank trackway, which is 68.5m in surviving length, 3.74m wide and 0.26m deep. One of the planks has been dendrochronologically dated to 3643±9 BC or later, making this the earliest dated trackway in Ireland. The site is oriented north–south, extending from Derrygreenagh Hill toward Croghan Hill. A small chert scraper was recovered from the vicinity of this site.

Department of Archaeology, University College Dublin, Belfield, Dublin 4