What was once a rath, the Irish term for a ringfort, an enclosed farmstead of the early medieval period defined by an earthen bank and an outer ditch known as a fosse, was levelled around 1950. To walk the field today is to see nothing obviously out of place. Yet from above, on satellite imagery, the ghost of the enclosure persists, its fosse still tracing an oval outline roughly 50 metres across at its longest point and 38 metres at its widest.

Ringforts of this kind were the standard unit of rural settlement in Ireland from roughly the fifth to the twelfth century, typically housing a single farming family and their livestock within a raised earthen bank. The Graigueooly example was already compromised well before it was levelled. Ordnance Survey mapping from 1839 and again from the revised edition of 1899 to 1900 both show a field boundary with its own ditch running northwest to southeast directly across the enclosure, bisecting it. The monument had therefore been cut through by agricultural reorganisation at some point before the first surveyors even arrived to record it, and whatever remained of the bank was subsequently removed around the middle of the twentieth century, apparently within living memory of those later consulted for local information.