Archaeological monitoring carried out ahead of the construction revealed a cluster of prehistoric features: two hearths, a pit, and a fulacht fia, all preserved beneath the surface of a site that might otherwise have passed unremarked.

A fulacht fia is a type of ancient cooking or processing site found in considerable numbers across Ireland, typically identified by a horseshoe-shaped mound of burnt and shattered stone alongside a trough that would once have held water. They are most commonly dated to the Bronze Age, though examples span a broad range of periods. At Ballynamuddagh, the fulacht fia was only partially excavated, with work focused on its western extent; the two hearths and the pit were fully investigated under Excavation Licence 00E0398. The findings were published by Gregory in 2002. What the hearths were used for, and how they relate to the fulacht fia and the pit nearby, places this small area somewhere in the domestic or craft activity of a community for whom this patch of Wicklow ground was, at some point, a working landscape rather than a neutral backdrop.