The ringfort at Forgney in County Longford belongs firmly to the second category. It sits, or rather sat, on a low rise in poorly drained pasture, and today there is nothing at ground level to indicate it was ever there at all.

A ringfort, or rath, is one of the most common early medieval monument types in Ireland, typically a circular enclosure defined by an earthen bank and an outer ditch, used as a farmstead or defended residence. The Forgney example was modest in scale, enclosing a roughly circular area of around thirty metres in diameter. What makes its story quietly instructive is the pace of its erasure. It was already absent from the Ordnance Survey's six-inch map of 1837, suggesting it had been substantially reduced even by that point. By 1976, a site inspection could still detect faint traces of the enclosing bank and its external fosse, the shallow ditch that would once have reinforced the boundary, though the original entrance had become unreadable. Since then, further levelling has removed even those residual traces, and the monument is no longer visible at ground level.