It is, by almost any conventional measure, barely there at all. And yet it was formally recorded as an archaeological monument, which raises an immediate and genuinely interesting question: what exactly has been found, and does it matter that no one can quite say?

The Archaeological Survey of Ireland visited the site in 2008 and recorded a roughly circular earthwork, approximately 2.5 metres north to south and 3 metres east to west, defined by a low scarp. A scarp, in this context, simply means a slight change in gradient where the ground drops away, suggesting the edge of a deliberately shaped feature rather than a natural rise. The mound sits in undulating, wet pasture about 410 metres south-west of a tributary of the Reask River, which also serves as the townland boundary between Knockballyfookeen and Cross. More intriguing still, five similar mounds begin just 10 metres to the east and continue eastwards, all clustered in the north-east corner of a single field. These companions are somewhat more pronounced, averaging between 0.2 and 0.4 metres in height. The difficulty, as the surveyors noted, is that the surrounding landscape is itself extremely uneven, a consequence of bedrock lying close to the surface and the long-term effect of water movement across the land. That natural irregularity makes it genuinely hard to separate deliberate human construction from the accident of geology. The record, compiled by Alison McQueen and Vera Rahilly and uploaded in October 2020, is frank about this uncertainty.

For anyone determined to visit, the site offers the particular experience of looking very hard at something that may or may not be there. The mounds were invisible on orthophotography taken between 2005 and 2018, so satellite images will not help with orientation on the ground. The wet pasture setting means the ground is likely to be soft underfoot, and the area is most navigable in drier summer months. The Reask River tributary to the north-east provides a useful landscape marker. What a visitor is actually searching for is a barely perceptible rise in a field, accompanied by five equally modest neighbours, in a corner of Limerick where the land itself seems reluctant to give anything away.