The platform measures roughly thirty metres across and rises only a matter of centimetres above the surrounding ground for much of its perimeter, though it reaches about seventy centimetres at its south-south-west edge. A slight external fosse, or ditch, about two metres wide, traces the outer boundary, and a scarp defines the inner edge of what was once, almost certainly, a defended enclosure of some kind.

This is the kind of site that archaeology calls a ringfort, a form of enclosed farmstead that was widespread across Ireland from roughly the early medieval period onwards. Ringforts were typically built as protected homesteads for farming families of some local standing, with the enclosing bank and ditch serving as much to define status and contain livestock as to provide serious military defence. The Roscarban example is modest in scale but retains enough of its original shape to be read clearly in the landscape. Compiled by Michael J. Moore in the Archaeological Inventory of County Leitrim, published in 2003, the record notes that no original entrance has been identified on the ground. A field bank running roughly north-north-west to south-south-east lies just to the west, with a small spur connecting it to the southern edge of the enclosure, suggesting the surrounding field pattern has grown up around and partially incorporated the older monument over time.