A roughly circular raised area, about nineteen metres across, sits on a gentle north-east-facing slope, its edges scarped and defined, its interior dipping oddly downward from the centre in every direction. At the heart of it all is a sub-oval depression, nearly four metres across and close to a metre deep, half-swallowed by scrub. It is, in other words, a landscape that has been deliberately shaped, and then largely forgotten.

This is a rath, or earthwork ringfort, the kind of enclosed farmstead that was built and occupied across Ireland from roughly the early medieval period onward. Ringforts are among the most common archaeological monuments in the country, yet each one carries its own particular arrangement of banks, ditches, and interior features. At Greenane, the enclosing element is a scarped edge about four and a half metres wide and one and a half metres high, with an external fosse, essentially a ditch, running around it at a width of just over six metres. Beyond that lies a counter-scarp bank of earth and stone, low but measurable, ranging between half a metre and just under a metre on its inner face. The layering of scarp, fosse, and bank suggests a degree of deliberate defensive or enclosing effort, even if the site is modest in scale. The central depression is harder to explain without excavation; it may represent a collapsed structure, a filled-in souterrain (an underground stone-lined passage sometimes found within ringforts), or simply the result of centuries of settling ground.

The site was recorded and compiled by Denis Power, with notes uploaded in June 2013. Because the monument sits in low-lying, poorly-drained pasture, the ground underfoot is likely to be soft, particularly after rain, and sensible footwear is advisable. Dense scrub vegetation obscures much of the visible structure, which means the earthworks are easier to read by walking the perimeter than by standing in the middle. The views outward in all directions are reportedly good, which itself offers a clue to why the site was chosen: even a modest elevation in flat terrain can command considerable sightlines across the surrounding land.