The shape is roughly 44 metres across at its longest axis, with a noticeably straight edge to the south-west, and it sits quietly within a broader field system that the Ordnance Survey never thought to record on any of its historic maps. That omission is part of what makes the place curious: despite the absence of any cartographic acknowledgement, the enclosure forms part of what earlier observers described, with considerable enthusiasm, as the remains of an ancient city of great extent.

The phrase comes from Dowd, writing in 1896, who noted that the wider settlement complex had long prompted speculation about extensive building foundations spread across the landscape. Whether that description reflects genuine urban-scale archaeology or a more modest cluster of enclosures has never been fully resolved. The enclosure itself, referred to as Fort 3 in a 1942 study by Seán P. Ó Ríordáin and John Hunt, was identified from aerial photography and mapped as a D-shaped earthwork, a form that enclosures, ringforts, and related monument types can sometimes take when one side follows a natural feature or an earlier boundary. Ó Ríordáin and Hunt noted that the D-shape may have been its original outline rather than the result of later erosion or alteration. A ringfort or enclosure of this kind would typically have served as a farmstead or defended homestead during the early medieval period in Ireland, though no specific date has been established for this example.

The enclosure sits approximately 200 metres south-east of the townland boundary between Coolfune and Killorath, within the north-western portion of the surrounding field system. Because it lies in pasture on former demesne land, access is not straightforward, and there is no formal visitor infrastructure. The earthwork is most legible from above, having been identified and re-confirmed through aerial photographs and satellite orthoimages taken at various points between 2005 and 2020, rather than through ground-level inspection. Anyone with an interest in the wider landscape context would find that tracing the field system on aerial imagery first gives a better sense of how this enclosure sits within what may once have been a much more densely occupied stretch of ground.