Yet from the air, in the right season, a faint oval outline emerges from the pasture at Ballyluddy in County Limerick, a ghost pressed into the soil by centuries of agriculture and road-building. This is the kind of monument that rewards patience and a certain tolerance for near-invisibility.

The site appears on the 1840 edition of the Ordnance Survey six-inch map under the name Raheennagaurlagh, where it is drawn as a circular enclosure already bisected at its southern side by an east-west road. Ringforts, sometimes called raths, were typically enclosed farmsteads of the early medieval period, defended by one or more earthen banks and ditches, and thousands of them survive across Ireland in varying states of preservation. This one has fared less well than most. When the Archaeological Survey of Ireland carried out fieldwork in 2008, they recorded an oval-shaped area measuring roughly twenty metres east to west and thirteen metres north to south, defined by a levelled bank approximately 4.7 metres wide. The bank retains a modest external height of around 35 centimetres on its western and northeastern arcs, but to the south it has been worn down to little more than a scarp, the point at which the road and centuries of land improvement have done their work. The townland boundary with Tullabeg runs along the southern edge, which may partly explain why the monument ended up straddling a route rather than being left in peace.

The site sits on a west-facing slope in improved pasture, and there is little on the ground to orient a visitor without prior preparation. The clearest view of the monument comes not from standing in the field but from aerial imagery. A cropmark, the kind of faint differential growth that appears when buried earthworks affect moisture retention in dry conditions, shows the oval outline on Ordnance Survey Ireland orthoimagery from 2005 to 2012 and on a Google Earth image taken in June 2018. If you do visit in person, the section of bank running from the southwest around to the northwest and from the northeast to the east offers the best chance of reading the earthwork, however slight. A sketch plan and measurements from the 2008 ASI survey remain the most useful tools for making sense of what the eye alone is unlikely to catch.