Together they formed the working infrastructure of a tannery, the kind of industrial installation that processed raw animal hides into usable leather through prolonged soaking in tannin-rich liquids. Tanneries were essential to early modern economies but are rarely preserved in any legible form, which makes the survival of this one, even as a subsurface trace, quietly remarkable.

Archaeological testing carried out under licence reference 97E0374, and reported by Bennet in 1998, revealed the pits arranged in three rows of seven, each measuring roughly 1.4 metres by 1.1 metres and dropping to a depth of about 1.1 metres. Their even spacing and consistent construction, wood lining, waterproofed with marl, suggest a deliberate and organised layout rather than piecemeal development. The pits were also found to relate to standing walls, indicating that at least part of the structure above ground was still visible or traceable at the time of excavation. The site is interpreted as post-medieval in date, placing it broadly in the period after the sixteenth century, when small industrial operations of this kind were becoming more common in Irish towns and their fringes. The proximity to the Slaney, approximately 130 metres to the south-west, would have been no coincidence; tanneries required a reliable water supply in large quantities, and rivers were the obvious solution.