It measures eight metres north to south and three metres east to west, and its lean-to roof would have risen to no more than about 1.6 metres at its highest point. That combination of features, the deliberate sinking into the hillside, the cramped headroom, the proximity to water, and above all the near-total invisibility from every approach, points strongly to a single purpose: this was almost certainly the site of a poteen still.

Poteen, an illicit distilled spirit traditionally made from grain or potatoes, has a long history in rural Ireland, where its production was driven underground by excise laws and the persistent attention of revenue officers. A still of this kind depended on concealment and on a reliable water source, both for the distilling process itself and for cooling the condensing coil. A location dug into a hillside beside a stream satisfied both requirements neatly, and the low roof would have reduced the visible profile of any smoke or steam still further. The structure survives in good condition, which is itself a small surprise given how thoroughly such sites were meant to be forgotten.