Not dramatically, not through any single recorded event, but quietly, incrementally, in the way that agricultural land tends to absorb what lies within it. A site that was still measurable and described in detail in 1983 had left no visible surface trace by the time aerial photography captured it in November 2011.

A ringfort, sometimes called a rath, is a roughly circular enclosure defined by one or more earthen banks and ditches, typically associated with early medieval settlement in Ireland, and often sited on elevated ground for drainage and visibility. The Piercetown example followed this pattern closely. When described in 1983, it consisted of a circular raised area approximately 28 metres across, enclosed by an earthen bank reaching up to 2.5 metres in height. The natural hillock appears to have been deliberately shaped, its slopes cut back or scarped to produce a flat interior platform. By 1837, when the Ordnance Survey recorded it on their Fair Plan map, the site was already being read as historical rather than functional, depicted as a circular enclosure ringed with trees and simply annotated as a fort. That map entry is now one of the clearest surviving impressions of what the monument looked like. Farm buildings sit immediately to the south and east of the site, and the gradual encroachment of agricultural activity is the most likely explanation for the levelling that followed. The monument was placed on the Register of Historic Monuments, as listed in Iris Oifigiúil, on 11 February 1975, a formal recognition that came too late to prevent further deterioration. A second ringfort survives approximately 200 metres to the south-south-east, which makes the loss of this one feel more pointed rather than less.