2021:804 - Derrybrock, Laois

Archaeological monitoring of excavations associated with the Barrow Blueway development was carried out on various dates between October 2020 and April 2024. The development comprised the upgrade of the existing navigation towpath between Lowtown and Athy, Co. Kildare. The Environmental Impact Statement for the project recommended monitoring of excavations at locations where the route passes in the vicinity of recorded monuments. The maximum depth of excavation required to facilitate the new compacted stone and dust surface was 0.35m.

Archaeological monitoring was carried out on the west bank of the canal, north of Camac Aqueduct at Derrybrock, Co. Laois, on 6 April 2021. There are two upstanding milestones along this section of the route. The milestones consist of dressed limestone pillars, both inscribed with the number ‘38’, indicating the distance from Dublin in old Irish miles. Early ordnance survey maps show the site of Ballymanus Castle (LA014-036) in the middle of the canal, suggesting any extant remains of the castle were removed when the canal was built in 1784. It was noted that the existing canal towpath is raised several meters above the adjoining field to the west indicating the towpath consists of made ground.

Monitoring revealed 0.05m of dark grey/brown silt topsoil, over 0.1m of light grey/brown sandy silt, over mixed grey/brown silty sand and gravel and dark grey/brown coarse sand and gravel with occasional inclusions of brick fragments and mussel shells, and modern rubbish including plastics, timbers and cable wire. As excavations proceeded to the north the light grey/brown sandy silt overlay yellow/brown sandy clay.  No archaeology was found.