A cashel is a stone-walled ringfort, the Irish equivalent of the earthen ráth, and these circular enclosures were the farmsteads and defended residences of early medieval Ireland, typically dating from roughly the fifth to the twelfth centuries. At Ballinscoola, both examples have collapsed so thoroughly that the stonework has effectively dissolved back into the landscape, leaving only the faint memory of a shape.

When the archaeologist O'Kelly surveyed the site in 1942 to 1943, the more substantial of the two cashels was described as a circular space enclosed by what appeared to be a stone bank, though none of the original facing stones remained visible. The entrance, positioned on the south side, was only barely discernible even then. Its overall diameter was recorded at approximately 100 feet, or 30 metres. The structure sat on a very low limestone hill, itself subdivided by a system of what O'Kelly identified as ancient fences, suggesting the landscape around the cashel had once been carefully organised. The second fort lay immediately to the west and had fared considerably worse, with only the slightest trace surviving. It was presumed to have been roughly similar in scale, also around 30 metres across. By the time an aerial photograph was taken for the Archaeological Survey of Ireland in January 2003, even the better-preserved example had been reduced to a barely visible outline on aerial imagery, detectable through Digital Globe photographs rather than any obvious feature on the ground.

For a visitor, this is firmly a site for those who find satisfaction in the nearly invisible. The cashels sit on low-lying limestone ground at Ballinscoola in County Limerick, and there is nothing here that will announce itself. The surrounding field system, with its traces of ancient boundaries, may actually offer as much to observe as the fort outlines themselves. Low winter light or a dry summer, when grass growth is uneven, can occasionally bring faint earthwork traces into relief in otherwise featureless fields. The site record was compiled by Caimin O'Brien and uploaded to the national record in March 2020, and the ASI aerial photograph reference ASIAP 349/13 remains the clearest documentation of what survives.