No earthworks, no banks, no traces of the enclosing ditch that would once have defined this site remain visible. What does persist is a piece of local legend: that this vanished fort was connected by an underground tunnel to a neighbouring ringfort known as Lissmilleen, located a short distance away.

A rath, to use the Irish term, was a roughly circular enclosure defined by one or more earthen banks and ditches, used as a farmstead or settlement during the early medieval period, broadly the fifth to twelfth centuries. A univallate rath, like the one recorded here, had just a single such enclosing bank. The Tarmon example is catalogued in C. Toal's North Kerry Archaeological Survey, published in 1995, which places it in a landscape dense with such sites. The tunnel legend connecting it to Lissmilleen belongs to a familiar category of Irish folklore attached to ringforts, where underground passages, sometimes called souterrains (stone-lined underground passages associated with early medieval settlement, likely used for storage or refuge), appear either as genuine archaeological features or as imaginative explanations for the strangeness of these places. Whether the tunnel here was ever a real souterrain, or purely a product of local memory filling in the absence of visible remains, is not recorded.