On paper, that sounds reasonably substantial. On the ground today, the reality is considerably more elusive. What remains is a very low circular platform, about 37 metres across, its edges marked only by the faint trace of a fosse, a shallow surrounding ditch, some 8 metres wide. The shape the mapmakers saw and the shape that survives are not quite the same, which suggests either that the centuries between then and now have been unkind to the earthwork, or that the original surveyors were interpreting something already half-dissolved into the pasture.

Enclosures of this kind are scattered across the Irish countryside and were used across a wide span of prehistory and the early medieval period for purposes that varied considerably, from settlement and stock management to ritual use. Without excavation it is rarely possible to say which function any particular example served, and Slieveroe offers no obvious clues beyond its form and setting. The undulating grassland around it is the sort of landscape that tends to preserve low earthworks precisely because it has never been worth the effort of ploughing flat, and the platform itself has endured, however faintly, because the ground here has been left largely undisturbed. That the fosse is still legible at all, even as a faint outline, speaks to how slowly such features disappear when grazing rather than tillage is the main land use.