Near Glasnamullen in County Wicklow, a circular feature roughly twenty metres in diameter was recorded on the Ordnance Survey's first edition map of 1838, the great nineteenth-century mapping project that captured Ireland's landscape in extraordinary detail before much of it changed beyond recognition. A circle of that size, if it were an earthwork enclosure, could have represented any number of things: a ringfort, a cashel, a stock enclosure, or something older still. The map suggests something was once visible and considered worth recording. What exactly, remains uncertain.

When investigators visited the site in 1989, they found it under mature plantation forestry, the kind of dense commercial woodland that can entirely swallow earthworks, suppress surface features, and make reading a landscape close to impossible. Nothing of archaeological significance was noted at that time. It is worth remembering that the absence of visible evidence is not quite the same as an absence of archaeology. Plantation can both obscure features and, in some cases, protect them beneath undisturbed soil. The 1838 cartographers were recording something on the ground; what survives below the surface, if anything, is another question entirely.