What makes it worth pausing over is how legible it remains: the bank, the ditch, and the single narrow entrance are all still readable in the ground, even after centuries of agricultural activity and more recent drainage works that have, paradoxically, sharpened rather than erased its outline.

This is a univallate ringfort, meaning it has a single enclosing bank rather than the double or triple rings found at more elaborate sites. Ringforts of this kind, known in Irish as raths when earthen, were the dominant form of rural settlement in early medieval Ireland, typically serving as enclosed farmsteads for a family and their livestock. The Aghanagran example is a sub-circular enclosure measuring roughly 24 metres north to south and 26 metres east to west. Its earth and stone bank stands 2.6 metres high on the outer face and about 1.2 metres above the interior floor, with a base width averaging around 5 metres. Outside the bank runs a fosse, essentially a defensive or boundary ditch, measuring 1.3 metres wide and 1.2 metres deep. Access to the interior is through a gap of approximately 3 metres on the north-north-east side, the original entrance. Modern drainage operations have deepened the fosse and heightened the bank somewhat, but the basic structure documented in the North Kerry Archaeological Survey of 1995 by C. Toal remains intact. The interior sits at a higher level than the surrounding ground, which is typical of sites where centuries of occupation and accumulated material have gradually raised the floor inside the enclosure.