The hachuring used by the cartographers describes its outline in the manner of a grove, a deliberate planting, something cultivated rather than ancient. Yet that tidy arboreal circle may be concealing something considerably older beneath it.

The most likely explanation is that the enclosure began life as a ringfort, the circular earthen or stone enclosures built across Ireland from roughly the early medieval period onwards, used variously as farmsteads, places of shelter, and sites of local social importance. Thousands survive across the country, though many were levelled by agricultural improvement or quietly absorbed into the landscape. At Sheean, the evidence suggests a different fate: rather than being cleared, the old circular boundary was reused sometime after 1700 as the framework for a tree-ring, a fashionable landscaping feature of the post-medieval period in which landowners planted rings of trees, often on elevated ground, as ornamental or practical windbreaks. The original earthwork would have provided a ready-made circular form, and the trees grew to obscure whatever remained of the earlier structure. By the time the Ordnance Survey recorded it in the 1830s, the site read as landscape rather than archaeology.