To a casual eye it might read as nothing more than a faint undulation in a pasture, but it is the remnant of a ringfort, the kind of enclosed farmstead that tens of thousands of Irish families occupied during the early medieval period, roughly between the fifth and twelfth centuries. Ringforts typically consisted of a circular area defined by an earthen bank and ditch, enclosing a homestead and its outbuildings, and the one at Clonkeady follows that general form, though time and agriculture have softened its edges considerably.

What makes the site quietly interesting is the way successive maps have recorded its slow erosion. The 1834 edition of the Ordnance Survey six-inch map shows a circular embanked enclosure with an external diameter of around 45 metres, a reasonably substantial structure. By the 1907 edition, the same feature had been reduced in the cartographer's eye to a small D-shaped field measuring roughly 33 metres across, the straight edge of the D reflecting the encroachment of a field boundary along its eastern side. On the ground today, the visible area measures approximately 32.5 metres east to west, and a field bank running roughly north-northwest to south-southeast cuts into the perimeter at the east. That bank is the agent of the D-shape: what was once a full circle has been clipped by agricultural reorganisation at some point between the two survey dates, leaving the monument slightly truncated but still legible as a raised, grass-covered platform.