The site at Coonealmore is a rath, the Irish term for a ringfort, which was typically a circular enclosed farmstead used during the early medieval period, roughly between the fifth and twelfth centuries. Most were built from earth rather than stone, which means time and farming have not been kind to them. This one sits on a low rise, just perceptibly higher than its surroundings, measuring roughly 26.8 metres north to south and 25.8 metres east to west, its boundary marked by a low earthen scarp rather than any dramatic rampart.

What makes the Coonealmore rath worth pausing over is the way the landscape around it quietly encodes its former structure. A fosse, the defensive ditch that once encircled a rath outside its main bank, no longer reads as open ground. Instead, it survives as a band of dense rushes and irises about four to four and a half metres wide, slightly sunken on the south-western arc, the wetness of the soil keeping the vegetation distinct long after the earthworks themselves have blurred. Beyond that, a strip of flat, grassy ground on the south and west sides may represent a levelled outer bank, though it cannot be traced all the way around. The interior of the enclosure has a gently domed profile, sitting roughly 0.6 metres above external ground level at the south and 0.85 metres at the north, that small elevation being typical of a site that was deliberately raised or that has simply accumulated over centuries of use. A poorly defined break in the scarp on the southern side, with what appears to be a narrow causeway crossing the rush-filled fosse, suggests that the original entrance faced south, towards drier ground.

The rath is considerably degraded now, dotted with gorse and brambles, and a field drain cuts across the ground a few metres to its north. But the rush-filled arc on the south-western side is the detail worth looking for: it is a rare case where a vanished ditch announces itself not through archaeology but through botany, the irises and rushes doing the work that excavation might otherwise have to do.