To an untrained eye it reads as nothing more than a slight unevenness in the pasture, but the oval outline, roughly 45 metres at its longest and 36 metres across, follows too deliberate a course to be accidental. A low bank of earth and stone, now worn to a height of only 20 to 30 centimetres and a width of around 2 metres, traces the perimeter of a ring fort, the kind of enclosed farmstead that was the typical unit of rural settlement in early medieval Ireland, typically housing a single family and their livestock within an earthen bank and sometimes a surrounding ditch.

What makes Lismacmurrogh quietly telling is how much has already been lost. A report filed in 1976 noted the presence of an external fosse, that is a defensive ditch, and a second outer bank beyond it, which would have given the site a more substantial double-ringed appearance. Both features have since been levelled, most likely through generations of agricultural activity, leaving only the innermost enclosure in any discernible form. The original entrance, which in surviving examples of this monument type is often marked by a gap or a slightly raised causeway crossing the fosse, is no longer recognisable. Outcrops of bedrock push through the interior, suggesting the ground here was never entirely workable, which may partly explain why the interior itself was not ploughed flat along with the outer earthworks.