That discrepancy alone is worth pausing on: the first Ordnance Survey six-inch map, produced in 1839, recorded it as distinctly oval, measuring roughly 42 metres on its northwest to southeast axis and about 27 metres across. By the time the revision was completed between 1899 and 1902, the same feature was being described as circular, with a diameter of around 45 metres. Whether the ground itself had changed, or simply the eye of the surveyor, is not recorded.

Enclosures of this kind are among the most common, and most quietly ambiguous, features in the Irish landscape. They are typically ring-shaped earthworks, defined by a bank and ditch, and are associated most often with early medieval settlement, though some are considerably older. They served as boundaries for farmsteads, as enclosures for livestock, or sometimes as sites with ritual or ceremonial significance. At Kilmanaheen, the picture is complicated slightly by the presence of a second enclosure located approximately 60 metres to the south. Paired or clustered enclosures are not unusual in Ireland, and they may reflect successive phases of occupation, or related but distinct activities carried out at the same general location over generations. Without excavation, it is difficult to say more.

What is certain is that the site is now well concealed. The vegetation that has grown over it since the nineteenth century makes its earthworks difficult to read from ground level, and the rough pasture around it does little to aid orientation. It is the kind of place that rewards knowing what you are looking for before you arrive.