The raised platform measures nearly seventy metres across, making it a notably substantial example of its type, yet much of what once defined it has been absorbed by the working landscape around it. The eastern and southern arc of the enclosing bank and its accompanying ditch have been levelled entirely, while the south-western stretch has been folded into a field boundary, so that the modern agricultural grid and the early medieval one now share the same line of earth without either announcing the fact.

A ringfort, sometimes called a rath, is an enclosed farmstead of the early medieval period, typically dating to somewhere between the fifth and twelfth centuries. Thousands survive across Ireland in varying states of preservation, but their individual details often tell particular stories. At Lisduff, the bank that remains reaches a maximum height of just over a metre and a width of more than seven metres, suggesting it was originally a substantial construction. Beyond it ran an external fosse, a defensive or boundary ditch, though here it is wide and relatively shallow, around a quarter of a metre deep where it survives. Within the enclosure, a possible house site was recorded in the south-western quadrant in 1975, and in the west-north-west sector there is a souterrain, an underground stone-lined passage or chamber that in early medieval Ireland served variously for storage, refuge, or as a means of concealed movement between spaces. The presence of a souterrain at Lisduff points to a settlement of some substance, one whose occupants invested real effort in the ground beneath their feet as well as the bank around them.