It is roughly D-shaped, its eastern side running almost straight while the western curves outward, and it sits not on level ground but carved into a slope, with a bank and ditch only where the hill demanded it and the southern side built up artificially to create something approaching a level platform. When the first Ordnance Survey six-inch maps were drawn in the nineteenth century, the fort appeared to sit right at the water's edge. Since then, the shoreline of Lough Gur has receded, and the monument now stands some forty metres back from the lake. That quiet shift in geography is itself a reminder of how much this landscape has changed around its oldest features.

The fort was noted as early as 1833 by Croker, who described it as a square earthwork with a grass-covered cairn at one corner, built largely of small stones with a few larger squared blocks mixed in. By 1944, O'Kelly was recording it in considerably more detail, measuring the surviving south face at around 3.6 metres high and the maximum diameter at roughly 25 metres, and identifying it as the focal point of an extensive system of earthen field boundaries and small enclosures running down the lower slopes of the hill. The fort was subsequently excavated, though the results remain unpublished. Finds including ring pins pointed to an early Christian date, broadly the period between the fifth and tenth centuries. What makes the site particularly dense is what surrounds it: a cashel, a stone circle, a possible settlement platform, and a crannóg, which is an artificial island dwelling, visible on Lough Gur itself, are all within a few hundred metres.

The site sits to the south of Knockfennell and northeast of Ardaghlooda Hill, with Loughgur House standing about 300 metres to the northwest. The D-shaped outline of the fort and traces of the associated field system remain clearly legible from aerial photography, and on the ground the platform character of the monument is easiest to appreciate from the northern side, where the scarp and ditch are most pronounced. The broader Lough Gur area is well served by walking routes, and the density of monuments in the immediate vicinity means that this ringfort tends to be visited alongside rather than instead of the better-known stone circle nearby. The entrance to the fort is no longer recognisable on the ground, so what you are reading is largely the shape of the thing itself, an irregular platform on a hillside that has been quietly here for over a thousand years.