It has appeared on Ordnance Survey maps since at least 1838, which confirms it was already a recognised feature of the landscape nearly two centuries ago, yet precisely what it was built for remains open to interpretation. The site is classified as a probable ringfort, possibly a cashel, though surveyors have been unable to be definitive.

Ringforts, which are enclosed farmsteads typically dating from the early medieval period, are among the most common archaeological monuments in Ireland, numbering in the tens of thousands. A cashel is essentially the same type of settlement but built using stone rather than an earthen bank. At Treanlaur, the enclosure measures roughly 25 metres north to south and 20 metres east to west. Its perimeter is defined by a stony scarp rising to about 0.8 metres on the south-west side, and in places this scarp appears to be faced with drystone walling, which is what nudges it towards cashel territory. On the north-east side, the builders seem to have taken advantage of a steep natural drop in the ground, letting the landscape do some of the structural work for them. There is considerable loose stone tumble along that slope, and the interior, where it can be assessed at all, appears level and strewn with stones and boulders. The ridge itself is flanked at its base by two streams, with hazel, blackthorn, hawthorn, and dense ferns clothing the surrounding ground.

The blackthorn scrub that now engulfs the enclosure made close inspection difficult when surveyors visited, and it is likely to present the same problem to anyone who goes looking for it today. The enclosure sits on a north-north-west to south-south-east ridge in an area of rough, rocky pasture, and the vegetation is dense enough that the stony scarp and any surviving drystone facing would take some patience to locate and read properly.