Rathmurry, as the Ordnance Survey cartographers recorded it on both the 1838 and 1922 six-inch maps, is a rath, one of the ringfort-type enclosures built across Ireland largely during the early medieval period, typically serving as a defended farmstead for a family of some local standing. What makes this particular example quietly interesting is the way its builders worked the landscape rather than fighting it: on the eastern side, the steep natural fall of the ridge does the work of an earthen bank, folded into the structure so that the man-made and the geological are almost indistinguishable.

The enclosure measures roughly 24.8 metres east to west, defined by an earthen scarp that survives to about 0.85 metres on the northern side but becomes indistinct toward the west. Around the north-west to north-east arc, and again at the south and south-west, remnants of a stone bank or wall can still be traced along the top of that scarp. It now presents as a low, loose jumble of stones about 2.4 metres wide, though at the north-west a run of contiguous set stones suggests that what remains is a fragment of original kerbing or internal facing, stones placed deliberately rather than simply tumbled. The interior itself is scattered with loose stone, and within it a rougher, squarish feature, approximately 8 metres by 7.5 metres, is outlined sporadically on three sides by a slight stone bank only about 0.2 metres high. Its northern limit is unclear, and its southern edge appears to follow a break of slope, with the ground dropping slightly beyond it. Whether this inner outline represents the footprint of a structure, a subdivision of the interior space, or something else entirely, the notes do not say, and the stones are keeping their own counsel.