The ringfort known locally as Lisduff, a name recorded as far back as 1914, sat in grassland above bogland to the south-west, a quietly unremarkable survival of early medieval Ireland until it was not. When archaeologists visited in June 1984, they found a subcircular earthwork roughly 35.5 metres north to south and 33 metres east to west, its overgrown bank still legible in the landscape. A rath, to give it its proper Irish term, is a ringfort defined by one or more earthen banks and ditches, built during the early medieval period as a farmstead enclosure. Lisduff's bank measured nearly three metres wide, and though much of the external fosse, the defensive ditch that would originally have ringed the outside, had been lost, traces of it remained at the south-west. A two-metre gap at the north-east was thought to be the original entrance.

By January 2010, when the site was inspected again, every trace of that earthwork had been removed. The bank, the fosse, the possible entrance gap, the gentle asymmetry of the ground: all of it gone, the slope presumably returned to agricultural use or otherwise absorbed into the working landscape. The local name Lisduff, from the Irish lios dubh meaning black enclosure or dark fort, suggests the site carried some identity in local memory long before formal recording began. Neary noted it in 1914. The 1984 inspection gave it measurements and a plan. The 2010 visit found nothing to measure at all. What the record preserves now is the description of something that had already become absence, the dimensions of a disappeared place.