The cartographers of that first six-inch edition marked it with hachures, the small radiating lines used to indicate a raised or defined earthwork, suggesting that at the time of their survey the feature still held enough shape to be recorded with some confidence. It was almost certainly a ringfort, the most common type of early medieval settlement in Ireland, typically consisting of a circular bank and ditch enclosing a farmstead or family compound. Tens of thousands are known across the country, yet each one represents a particular household, a particular patch of land, claimed and defined sometime between roughly the fifth and twelfth centuries.

By 1998, when the site was inspected on the ground, nothing remained visible. The hollow in the pasture had been improved, meaning the land had been drained, levelled, or otherwise worked over the generations until whatever earthwork once rose here was absorbed back into the field. It is a quiet kind of erasure, gradual rather than deliberate, and common enough across Ireland wherever agricultural improvement has been thorough. About 110 metres to the south-south-east lies a second possible enclosure, which suggests this part of Monanaleen may once have held more than one such settlement, though whether the two were contemporary or separated by centuries is impossible to say from what survives.