This one, a circular enclosure in rough pasture to the east of Killarney, offers nothing so cooperative. At ground level, it is entirely invisible, its presence known only because a surveyor recorded it on the Ordnance Survey six-inch map of 1846, marking out a circle roughly thirty metres across in the townland of Teernaboul.

Circular enclosures of this kind are generally associated with early medieval settlement in Ireland, the most familiar form being the ringfort, a farmstead defined by one or more earthen banks and ditches. Whether this site was ever a ringfort, a ceremonial enclosure, or something else entirely, the available evidence does not say. What the 1846 map preserves is at least the outline of something that was still legible to nineteenth-century eyes, even if the landscape has since closed over it completely. That gradual erasure is not unusual. Centuries of agricultural activity, drainage work, and the slow creep of vegetation can reduce a substantial earthwork to nothing detectable without excavation or aerial survey.