Not dramatically, not all at once, but across the span of a century of cartography, it went from a clearly defined embanked enclosure to something that mapmakers could only gesture at vaguely.

When the Ordnance Survey produced its six-inch map in 1839, the feature was recorded as a substantial embanked enclosure, an earthwork defined by a raised bank forming a rough ring, with an external diameter of somewhere between 65 and 70 metres. Embanked enclosures of this kind are found across Ireland and are typically associated with early medieval settlement or ceremonial use, the bank serving as a boundary marker or defensive perimeter for a farmstead or ringfort. By the time a later edition of the map was produced in 1925, whatever remained had lost its definition entirely, reduced to a formless area of roughly similar extent. At ground level today, nothing is visible at all in the surrounding pasture, and aerial photographs taken in 2005 show the site sitting unplanted within an otherwise planted coniferous wood, a gap in the tree cover that might be the only outward sign that something is there.

That deliberate absence of planting is telling. It suggests the site was recognised and left clear even as the forestry grew up around it, preserved in outline if not in substance. The enclosure itself may have been levelled by centuries of agricultural activity, but the 86-year gap between the two map editions captures, with unusual clarity, the slow process by which an earthwork passes from monument to memory to near-nothing.