A circular enclosure, the kind of ringfort or field boundary that once peppered the Irish landscape, was carefully recorded by Ordnance Survey cartographers working in 1841 and 1842. By the time the next major survey was completed in 1898, it had vanished from the map entirely, and today no trace of it survives on the ground.

The gap between those two surveys, roughly half a century, is when the enclosure disappeared from the record and apparently from the earth. Whether it was levelled for agriculture, robbed for building stone, or simply eroded beyond recognition is not known. Circular enclosures of this type, often referred to as ringforts, were typically built in the early medieval period as enclosed farmsteads, their boundaries formed from earthen banks or stone walls. They are among the most common archaeological monument types in Ireland, yet thousands have been lost to land clearance and intensified farming since the nineteenth century. The Lacka Beg example is a small illustration of that broader disappearance, made legible only because the 1841 to 1842 Ordnance Survey happened to catch it at the right moment.