Sometime after 1990, a ringfort that had survived for well over a thousand years was destroyed, erased from a ridge in County Wicklow where it had quietly occupied the landscape since early medieval Ireland.

A rath, as this type of site is also known, is a roughly circular enclosure defined by an earthen bank and sometimes a surrounding ditch, used as a defended farmstead in early medieval Ireland, typically between the fifth and twelfth centuries. The Ballykillageer example was a substantial one, measuring approximately 53 metres north to south and 49 metres east to west, its perimeter formed by a bank of earth and stone between four and six metres wide, though rising only about half a metre in height. It sat along an east-west ridge, with the ground dropping away gently to the south, a position that would have offered good visibility and reasonable drainage. Unusually, surveyors found no trace of an entrance gap through the bank and no external fosse, the ditch that typically runs outside a rath's enclosing bank. The interior was level and gave nothing away. When the site was visited and recorded in 1990, it was still intact. By the time its description entered the published Archaeological Inventory of County Wicklow in 1997, the phrasing had already shifted to the past tense.

There is nothing to visit at Ballykillageer now. The physical site is gone, which gives the record a particular kind of weight. What the 1990 survey captured was essentially a last sighting, a description of dimensions and materials for something that would not survive the decade.