The slight swelling in the earth, roughly sixteen metres north to south and fourteen metres east to west, is easy to miss, and without the cartographic record there would be little reason to pause here at all.

The Ordnance Survey six-inch map of 1837 shows the enclosure with reasonable clarity, drawn as a circle approximately twenty metres in diameter, sitting on the southern side of a northwest to southeast ridge where the ground drops away steeply to the south. Circular enclosures of this kind are a common feature of the Irish landscape, typically interpreted as the remains of ringforts, the enclosed farmsteads that were the basic unit of rural settlement throughout the early medieval period. What makes the Lugdoon example quietly telling is what happened to it between surveys. By the time the revised Ordnance Survey edition was published in 1913, the enclosure had vanished from the map entirely. The 1837 depiction also shows an L-shaped building overlying the western side of the enclosure, suggesting that agricultural development had already begun to encroach upon and reshape the site. That building, and the gradual levelling of the monument it may have accelerated, left behind only the faint topographical ghost visible today.