From the air, the soil over Powerstown revealed what could not be seen at ground level: the cropmark of a roughly circular enclosure, around 35 metres in diameter, defined by a fosse, the term for a defensive or boundary ditch dug around early settlements and enclosures. The photograph, taken as part of the Cambridge University Collection of Aerial Photography, caught the buried outline at a moment when differential crop growth made the old ditch legible from above, a technique that has quietly transformed the map of Irish archaeology over the past century.

The enclosure is not entirely intact, even as a cropmark. A field boundary running east to west cuts across the northern portion, and the aerial signature only survives south of that line. At the centre of the southern arc, a dark soil stain suggests a filled-in depression, and here the 1839 first-edition Ordnance Survey six-inch map offers an unexpected footnote: it marks a small roughly circular sand pit at almost exactly that spot. Whether the pit predates, postdates, or is entirely coincidental to the enclosure is unclear, but the overlap is difficult to ignore. More recent changes to the landscape have been less ambiguous. Kilcarrig Quarry, situated nearby, expanded southward between 2005 and 2009, crossing below the enclosure, and by 2017 had extended to its east as well. The effect is that the surviving southern portion of the enclosure now sits on a kind of peninsula, projecting into the quarry on three sides.