On a gentle south-west-facing slope in Glen William, County Waterford, a quietly puzzling feature sits in the landscape: a roughly circular grass-covered area, around thirty metres across, that was once something considerably more substantial. Two successive Ordnance Survey maps, from 1840 and 1927, recorded it as a circular embanked enclosure with an external diameter of between forty-five and sixty metres. By the time anyone thought to document it closely on the ground, it had been reduced to its present, diminished form.

Locally, the site was known as a lios, the Irish term for a ringfort, the type of enclosed farmstead built in their thousands across Ireland between roughly the fifth and twelfth centuries. Ringforts typically consist of a raised earthen bank encircling a domestic area, sometimes accompanied by an external ditch, and they served as the basic unit of early medieval rural settlement. At Glen William, the enclosure was described as having been removed around 1950, most likely levelled during agricultural improvement work, a fate that befell a great many such sites in the mid-twentieth century when field drainage and mechanised farming made earthworks inconvenient. What survives today is a subcircular grass-covered area measuring roughly thirty-two metres east to west and twenty-nine metres north to south, defined by a flat-bottomed fosse, that is, a ditch, between five and seven metres wide but now only around ten to twenty centimetres deep. A portion of the outer bank, about thirty-six metres in length along the north-north-west to north-east arc, still stands to an internal height of one and a half metres, where it has been absorbed into a curved field boundary and so escaped clearance. The discrepancy between the dimensions recorded on the nineteenth and early twentieth-century maps and what is visible now gives a rough measure of how much was lost in that single act of removal.