This is a rath, the Irish term for a ringfort, the type of enclosed farmstead that was built in large numbers across Ireland during the early medieval period, roughly between the fifth and twelfth centuries. Most were homesteads for farming families of middling status, defined by a circular or oval earthen bank that served as both boundary and a degree of protection. The one at Cloonfeightrin sits on its ridge with a level, grassy interior and a commanding view over the bogland below.

The site's history of gradual absorption into the working landscape is part of what makes it worth attention. When the first Ordnance Survey six-inch map was made in 1838, the enclosure was recorded as a broadly oval feature, roughly 50 metres north to south and 65 metres east to west, ringed with trees, still legible as a distinct and separate thing. By the 1920 edition, that clarity was gone. The enclosure had been folded into a system of field boundaries, with the eastern side cut across by a north-west to south-east field wall. The earthen bank or scarp, which still stands to an external height of around 1.5 metres on the north side, has been put to work as a field fence around the whole circuit. Its outer slope has been faced with drystone walling, and on the southern arc a stretch of the original scarp appears to have been replaced by drystone construction entirely. A low stony internal rim, about a metre wide, runs along the top. The eastern side has been truncated by a straight north to south drystone wall. What began as an early medieval enclosure has, over the course of a century or so of farming, become structurally inseparable from the field system around it.