This is a rath, the most common type of early medieval settlement in Ireland, typically consisting of a roughly circular enclosure defined by an earthen bank and ditch, within which a farmstead once stood. What makes individual examples worth pausing over is how much physical presence they retain despite centuries of agricultural use. Here, the circular area measures approximately thirty metres in diameter, defined by a scarp between 0.7 and one metre high, with an external fosse, or ditch, roughly 2.2 metres wide and up to 0.6 metres deep in places.

A report from 1976 noted that the original entrance to the enclosure may have been positioned on the eastern side, which was a common orientation for raths, thought by some researchers to reflect practical considerations around morning light and prevailing wind. Beyond that observation, the documentary record for this particular site is sparse, which is itself unremarkable. The majority of Ireland's several thousand surviving ringforts have no written history attached to them at all. They were built and occupied roughly between the sixth and twelfth centuries, used by farming families of varying social status, and then quietly absorbed into the landscape as agriculture changed around them. The fact that this one in Legan survives with its scarp and fosse still legible is a function of the land remaining as pasture rather than being ploughed out.