The uncertainty is not a failure of research but rather the nature of the thing itself: a ghost in the landscape, glimpsed once from the air and since slipped back into invisibility. That single sighting is enough to earn it a place in the archaeological record, even if the ground gives nothing away to the casual eye.

The potential site at Ballytrasna came to light during the Bruff aerial photographic survey of 1986, when a D-shaped cropmark was recorded, reference Bruff 64, AP 4/3681. Cropmarks form when buried features, walls, ditches, or filled pits, affect the growth of surface vegetation; in dry summers especially, the outline of a long-vanished structure can appear in a ripening field as if briefly resurfacing. Here, the straight northern side of the D-shape appeared to align with a field boundary, suggesting some structural logic beneath the grass. The site sits on a gentle north-facing slope in undulating pasture, close to a spring, with a separate recorded enclosure lying about 115 metres to the north-west. Notably, the site does not appear on Ordnance Survey historic mapping at any period, meaning it was either overlooked or had already lost all surface expression before systematic recording began. A hollow depression was visible on an Ordnance Survey Ireland orthophoto taken between 2005 and 2012, but by the time Digital Globe and Google Earth imagery was examined, between 2011 and 2017, no trace remained. The record was compiled by Alison McQueen and Vera Rahilly and uploaded in July 2020.

There is little to see on the ground today, and that is precisely the point. The pasture near Ballytrasna looks like ordinary County Limerick farmland, and for most of the year it is. The spring adjacent to the site is a small practical clue that settlements, enclosures, a term referring broadly to areas bounded by earthen banks or ditches for habitation or livestock management, have long favoured such spots. Anyone curious about the area would do well to cross-reference the 1986 aerial survey image against current mapping, as the D-shaped outline is most legible in that original photograph rather than in any subsequent ground-level visit.