This report presents the results of archaeological investigations carried out on behalf the National Roads Authority and Kildare County Council as part of Archaeological Services Contract No. 4? Resolution, Prumplestown to Powerstown, prior to the commencement of construction on this section of the N9/N10 Kilcullen to Waterford Scheme: Kilcullen to Powerstown. The work was undertaken under Monuments Section Registration Number E2567, in the townland of Burtonhall Demesne, Co. Kildare. The Minister for the Environment, Heritage and Local Government, following consultation with the National Museum of Ireland, directed that Angus Stephenson of Headland Archaeology Ltd should proceed with archaeological resolution. Archaeological testing carried out under Archaeological Services Contract, Test Excavations Contract 3, Prumplestown to Powerstown, under Ministerial Direction Number A021/000, on this site in 2005 identified the possible remains of a fulacht fiadh (in Trenches 6, 7 and 8). This was seen to measure at least 9 m by 6 m with an average recorded depth of horizontally?lain burnt deposits of 0.12 m. The fulacht fiadh continued to the field boundary and beyond the zone of the Compulsory Purchase Order (CPO). An outlying posthole was also noted during the testwork. Full archaeological resolution was conducted on this site between 7 February and 30 March 2006. This revealed the remains of a mound of shattered stones and black ash, which can be confidently described as a fulacht fiadh, dating to the early Iron Age. The layers of burnt material covered an area of 16 m by 10 m within the CPO zone and covered a central rectangular trough, 2.10 m long, with an oval recut through it, near and below the modern field boundary. The earlier trough had several stakeholes driven into its corners. Any interpretation of the function of the features cannot be conclusively proven but these sites are believed to have been used in prehistoric times for heating water for cooking, washing or similar activities using burnt heated stones. The interface between the burnt material and the underlying glacial till was irregular and many of the ash?filled anomalies below the mound are likely to have been naturally formed, although a few of these scattered features may have been archaeological pits and postholes. A later undated and backfilled stream channel cut through the middle of the mound. Some of the mound material had been used to bank up the modern field boundary which showed extensive evidence of animal burrows and tree roots.