At Killeen in County Mayo, a site was noted as a possible enclosure, the kind of roughly circular earthwork that would once have defined a farmstead or provided shelter for livestock in early medieval Ireland. The entry came from a local source in 1991, passed along through the channels by which folk memory and fieldwork occasionally meet.

When investigators visited in 1997, they found improved pasture and nothing else. No earthwork, no trace of a bank or ditch, no crop mark or soil discolouration to suggest something lying just beneath the surface. The land had been worked over, smoothed out, made productive in the agricultural sense, and whatever had prompted that original local report had either been misidentified or had disappeared under the pressure of modern farming. The site was recorded nonetheless in the Record of Monuments and Places, the statutory inventory of known and suspected archaeological sites in Ireland, because absence of evidence and evidence of absence are not quite the same thing in a landscape as thoroughly reshaped as this one.