Dug deep into the flat ground of a fairly level landscape, it was not found through chance but through a methodical process of geophysical prospection followed by targeted excavation across a large development area of roughly 75 hectares spanning the townlands of Loughsallagh, Portan, and Gunnocks. Of the sixteen locations judged to have genuine archaeological potential after initial testing, all but four proved worthwhile. This well, or water-hole, was among the most structurally complex of them.

The well itself was a substantial cut, measuring approximately 4.4 metres north to south and 3.6 metres east to west, dropping to a depth of 2.2 metres. Its sides were straight on three sides, with the northern end sloping gently before falling vertically to a flat base roughly 2.5 metres wide. What makes the feature particularly interesting is how it had been filled in, layer by layer, over time. Excavation directed by J. Whitaker between April and July 2019 revealed twelve distinct fills. The upper six were clayey silts, the accumulated residue of gradual silting, but the lower layers told a different sequence: a dump of 21 timbers in roundwood and brushwood form, then waterlogged, charcoal-rich material containing wood fragments, then a basal layer of burnt mound material, which is the debris associated with prehistoric cooking or industrial activity using fire-heated stones, alongside a single timber oriented north to south. Above the wood deposit lay peaty marl containing wood, charcoal, and hazelnut fragments. A solitary post-hole sat at the lip of the well on its eastern side, and a second steep-sided pit lay six metres to the east, though neither feature produced any artefacts. A cobbled surface of roughly 5.3 by 5.2 metres was located about three metres to the south-west of the water-hole, positioned just north of a field drain running on a west-north-west to east-south-east alignment, with a second drain on the same line roughly ten metres to the north.

The absence of artefacts means the well resists easy dating, but the burnt mound material at its base connects it to a type of activity well attested in the Irish prehistoric record, suggesting the site had a long and varied use-life before its final silting over. The cobbled surface and the alignment of the field drains hint at an organised working landscape around the water source, even if the precise period or periods remain open questions.