A rath, sometimes called a ringfort, is an enclosed farmstead of the early medieval period, typically defined by one or more banks of earth thrown up around a central living area. This one at Drumlane is modest in scale, roughly 41 metres across at its widest, and its position on the south-east-facing shoulder of a ridge suggests it was chosen for both visibility and drainage, the two persistent concerns of anyone building on Irish glacial terrain.

When surveyors described the site in 1968, they found an overgrown circular area defined by an earthen bank to the north-west, much of which had already been reduced to a low scarp. At its tallest point, on the north-east side, that scarp still stood about 1.8 metres high. An outer fosse, a defensive ditch running along the north-west across the spine of the ridge, was also recorded. There were gaps throughout the bank, though no one could confidently identify where the original entrance had been. By 1995, the south-west portion of the monument had been removed entirely, the kind of attrition that comes from agricultural pressure and the slow logic of land improvement. Archaeological monitoring carried out in 1998 within 50 metres of the rath, undertaken by Byrne and recorded as excavation licence 98E0500, produced no related material, so whatever domestic life once animated the enclosure has left no trace in the immediately surrounding ground.