The circular enclosure measures just over twenty metres across, and its enclosing bank, now much reduced by centuries of weathering and agricultural activity, survives to an external height of only half a metre in places. What remains is a faint but legible outline, the kind of feature that rewards a careful eye rather than a casual glance.

The site belongs to a class of monument known as a rath or ringfort, the most common archaeological monument type in Ireland. Ringforts were typically enclosed farmsteads occupied during the early medieval period, roughly between the fifth and twelfth centuries, though some may be earlier. They were built by farming families of varying social rank and served as both a domestic settlement and a means of enclosing livestock. At Doonflin, the enclosing bank is of earth and stone, and an original entrance gap, one metre wide, survives on the eastern side. Notably, the northern terminal of this gap is lined with a large upright slab, a small but telling detail that suggests a degree of deliberate construction at the threshold. Closer to the centre of the interior, a separate small circular hut site has been recorded, the likely footprint of a domestic structure that once stood within the enclosure.