In a pasture field at Rathnarrow in County Westmeath, there is a barrow so faint that it failed to appear on Ordnance Survey maps made in 1837 and again in 1913, and cannot be detected in modern aerial photography. What survives, if survival is even the right word, is a roughly circular depression in the earth, measuring around five metres north to south and just under five metres east to west, defined by a narrow, shallow fosse. A fosse is simply a ditch, in this case the defining feature of a ditch barrow, a form of prehistoric funerary or ritual monument where a circular enclosing ditch, rather than a raised mound, marks out a special area of ground. There is no visible trace of any accompanying bank.

When fieldworkers recorded the site between 1970 and 1972, they described it as barely visible even then. Its neighbours are more legible: two further barrows sit roughly fourteen metres to the south and thirty metres to the south-east, making Rathnarrow a small, quiet cluster of prehistoric monuments on ground that looks out over lower-lying land to the north. The ditch barrow itself was absent from both the Victorian-era and the Edwardian-era Ordnance Survey editions, which suggests it had already been reduced, by centuries of ploughing or grazing, to something cartographers either missed or judged too insubstantial to record. That it was noticed and documented at all in the early 1970s makes the record itself something of a minor act of archaeological persistence.