But the ground here has been shaped deliberately and with some precision: a roughly circular enclosure measuring around 51 metres north to south and 43 metres east to west, bounded by an earthen bank that still stands 1.7 metres high along the eastern to north-north-eastern arc, with a scarp of around 1.5 metres carrying the line elsewhere. A fosse, the external ditch that typically accompanied such constructions, runs along the northern to southern side, still measurable at 0.8 metres deep.

This is a rath, the Irish term for a ringfort, the most common monument type surviving in the Irish countryside. Built and occupied mainly between the sixth and tenth centuries, raths served as enclosed farmsteads for early medieval families, the earthen bank and fosse providing a degree of security for livestock and household alike. The Coorleigh example preserves much of its original circuit, though the bank shows two original-looking breaks, one to the south-south-east and one to the south-west, each around three metres wide, which may represent former entrances. A wider modern gap to the west, at roughly 2.6 metres, marks a later intrusion into the structure, probably a practical adaptation by farmers working the surrounding land across more recent centuries.

The survival of the fosse alongside a bank of this height gives a reasonable sense of what the enclosure once looked like from outside, when the ditch would have added considerably to the perceived height of the bank above it. That the whole thing remains visible in an ordinary grazing field, neither excavated nor especially managed, is part of what makes it worth pausing over.