The ringfort at Farnane sits immediately north of the farm buildings, hemmed in by a farm track, its circular form now so thickly wooded that it reads more as a small, stubborn copse than as the remnant of an early medieval enclosure. Ringforts, sometimes called raths, are roughly circular enclosures defined by an earthen bank and ditch, and were typically used as defended farmsteads during the early medieval period in Ireland. Here, the bank survives as a scarp, a pronounced slope rather than a standing wall, with trees planted on both the interior and exterior, which has the effect of both preserving and obscuring what lies beneath.

The site appears under the name Lissadoon on the 1840 Ordnance Survey six-inch map, where it is shown as a circular area enclosed by a bank, with a farmyard road running roughly a hundred metres to the east. By the time the 1897 OS twenty-five-inch map was produced, the ringfort had been incorporated into the southern end of a small, irregular field, and the field's south-eastern boundary follows the curve of the monument so closely that the field boundary itself becomes a kind of record of the earthwork's shape. The measurements recorded from that later map give an internal diameter of approximately twenty-seven metres and an external diameter of around thirty-four metres, figures consistent with a typical rath of modest proportions. Satellite imagery from 2011 to 2013, and again from 2018, confirms that the tree-covered mound continues to hold its ground just north of the farm buildings, surrounded on its accessible sides by the working farm track.

The site lies 230 metres north of the R506, and while it is not a formally managed heritage site with public access, its outline is legible from the road and from aerial and satellite imagery. The most informative approach is simply to look at historical mapping alongside modern satellite views; the way the 1897 field boundary bends to accommodate the ringfort's curve is one of those small, satisfying moments where land use and ancient geography coincide. The heavy tree cover means that visiting in winter or early spring, when leaf cover is minimal, would give the clearest sense of the scarp's profile. As with many such sites on private farmland, access should be sought from the landowner before approaching.