This one in the townland of Garbally, in the barony of Coshma in County Limerick, is notable largely for the uncertainty surrounding whether it is an archaeological site at all. Sitting in wet pasture roughly 150 metres south of the Morningstar River, which marks the boundary between Garbally and the townland of Bruff, the feature in question is a circular mark in the ground that may or may not be prehistoric. A ring-ditch, in the archaeological sense, is typically a circular or near-circular ditched enclosure, often all that remains of a burial mound after centuries of ploughing have levelled the central mound and left only the surrounding ditch as a faint trace in the soil. What sits in this Limerick field may be something considerably more mundane.

The site first came to light not through any planned survey but through an aerial photograph taken on 3 November 1984, catalogue reference BGE 1:5000 No. 50, commissioned as part of the groundwork for the Bórd Gáis Éireann Curraghleigh to West-Limerick gas pipeline. Scrutiny of that image suggested a possible ring-ditch, and the feature was recorded accordingly. It does not appear on any historic Ordnance Survey Ireland maps, which is not necessarily damning for a feature of this kind, as subtle earthworks frequently escaped the attention of nineteenth-century surveyors. A further look became possible with a Google Earth orthoimage dated 5 April 2006, which showed a circular cropmark, the kind of discolouration in vegetation that can betray buried features beneath a field. The difficulty is that this particular mark was assessed as looking rather more like the impression left by a ring-feeder, the circular metal frames used in modern farming to hold fodder for livestock, than anything of prehistoric origin. By the time later imagery was examined, including Ordnance Survey orthophotos from the period 2005 to 2012 and a Google Earth image from 20 September 2020, no surface trace of any kind was visible. The site is formally recorded with reference number LI031-187, and a separate earthwork, LI031-186, lies roughly 120 metres to the north-east.

There is, in practical terms, nothing for a visitor to see on the ground. The wet pasture shows no obvious surface feature, and the record compiled by Martin Fitzpatrick and uploaded in March 2021 carries the cautious verdict of doubtful antiquity. What makes this place worth knowing about is precisely that candour. Archaeological inventories are sometimes assumed to be catalogues of confirmed wonders, but they also document the ambiguous, the inconclusive, and the misidentified. A gas pipeline survey, a circular shadow in a 1984 aerial photograph, and the suspicion that a farmer's ring-feeder may have been mistaken for prehistory: the Garbally entry is a small, honest record of how difficult it can be to read the past from the air.