The enclosure at Cloonaherna is not ruined so much as layered over, its boundaries obscured by vegetation, its interior colonised by trees, and at least one section of its perimeter wall pressed into service as the foundation for a later field boundary. What survives is legible only in fragments, and yet the outline is still there if you know where to look.

The enclosure is roughly oval in plan, measuring approximately 42 metres on its northeast to southwest axis and around 35 metres across. It sits on a very gentle southwest-facing slope, with rough pasture, natural woodland, and rock outcrop to the northwest, and planted woodland encroaching from the northeast. Where the structure can still be traced, it takes the form of a collapsed drystone wall, a construction technique using stones fitted together without mortar, which was common across early medieval Ireland for ringforts and enclosures of various kinds. The surviving wall remnants are modest but measurable: an internal height of around 25 centimetres, an external height of around 45 centimetres, and an overall width at the base of 3.5 metres, suggesting the original structure was considerably more substantial. The Ordnance Survey recorded the enclosure on both the 25-inch map series and the 1921 edition of the 6-inch map, which at least fixes its outline at a point in time before tree planting and briar growth complicated matters further. A townland boundary cuts across the west-northwest sector, truncating the monument along its long axis, meaning the enclosure does not even belong entirely to itself anymore, divided as it is by an administrative line drawn across the landscape at some point after the structure ceased to function.

Visitors approaching the site would find the going difficult. Dense briars cover the northeast to southwest arc of the enclosure, and trees have grown up through this vegetation across much of the interior. The clearest surviving sections of the original wall are those running from southwest through west to northwest, where the collapsed drystone is still traceable on the ground. The later field wall built on top of the enclosure wall to the northeast is, in its way, as interesting as the monument itself, a small piece of evidence that someone, at some point, found the old boundary useful enough to reuse rather than clear away.