Within a few hundred metres of one another sit a stone circle, a structure known as Cahir Mortle, a second ringfort, and the subject of this entry: a ringfort set into pasture whose shape has shifted, on paper at least, from a clean circle to a raised D, depending on which century's survey you consult. That shifting outline is not mere cartographic inconsistency; it reflects how the monument has been read, used, and gradually absorbed into the working landscape over nearly two centuries of recorded observation.

A ringfort, sometimes called a rath or liss, is an enclosed farmstead of the early medieval period, typically defined by one or more circular earthen banks and ditches, known as a fosse, and used as a defended homestead for a family of some local standing. The Ballygeagoge example appears on the Ordnance Survey's first six-inch map of 1840 as a circular area enclosed by a bank, straightforwardly enough. By the 1897 twenty-five-inch edition, the picture had grown more complicated: the monument is recorded as a raised D-shaped area, defined by a scarp running from south-east around through south, west, and north-east, with a fosse and bank incorporating an external fosse that had been folded into an adjacent field boundary. A souterrain, an underground stone-lined passage typically associated with ringforts and used for storage or refuge, was recorded in the western quadrant on the Cassini edition of the six-inch map. In 1931, O'Shaughnessy and Carroll described the site as two moats or lisses with souterrains, suggesting either that the monument was read as a compound enclosure or that the nearby features were being considered together.

The monument sits roughly 40 metres west of the townland boundary with Ballinlyna Lower, and remains visible in satellite imagery taken between 2011 and 2013 as a circular area defined by a tree-lined fosse with a bank running from south-east around to north-west. A trackway cuts across the northern side running roughly east to west, which accounts for some of the breaks in the earthwork's profile. The land is in pasture, so access would depend on the goodwill of the landowner. Those who do get close should look for the subtle rise of the interior platform and the vegetation difference where the fosse and its tree line mark the enclosure's edge. The stone circle lying 264 metres to the east and Cahir Mortle 500 metres to the north-west make this corner of Mortlestown Hill an unusually dense patch of surviving early monuments, each one quietly going about the business of existing.