It is easy to walk past without registering what you are looking at, but the circularity is deliberate and old: a roughly circular enclosure, approximately 17 metres north to south and 16 metres east to west, defined by an earthen bank that still rises to a maximum internal height of 1.2 metres. That it survives at all, in agricultural land that has been worked for centuries, is itself a small oddity worth pausing over.

Enclosures of this kind are among the most common, and most debated, monuments in the Irish countryside. They are broadly interpreted as the remains of ringforts, the farmstead enclosures of early medieval Ireland, typically dating from roughly the fifth to the twelfth century, though some may be earlier or later. A ringfort, in its simplest form, is a circular area enclosed by one or more earthen banks and ditches, originally used as a defended farmstead or settlement. What makes the Rouryglen example quietly interesting is the detail of a stone field fence running along the outer face of the bank from the north-north-west around to the north-east. This suggests that at some point, probably in the post-medieval period, a later farmer recognised the bank as a ready-made boundary and built onto it, essentially pressing an ancient structure into service for more mundane purposes. The old and the functional became the same thing, which is perhaps why the monument survived.