A subcircular enclosure, roughly 35 metres east to west and 30 metres north to south, was recorded on the 1834 edition of the Ordnance Survey six-inch map, labelled in the distinctive gothic lettering the surveyors reserved for antiquities, simply as a fort. Today, in the same field, there is nothing to see.

The word fort, as used by those early OS surveyors, generally referred to a ringfort, the most common type of early medieval settlement monument in Ireland, typically a circular area enclosed by one or more earthen banks and ditches, used as a farmstead or place of refuge. Thousands were recorded across the country during that first great national mapping effort of the 1830s. The one at Legnacreeve sits on a gentle south-facing slope, with a small canalised stream running east to west some 60 metres to its south, the kind of modest, practical setting that was typical for such enclosures. At some point between 1834 and the present, agricultural improvement erased whatever earthworks remained, leaving the monument to exist only in the cartographic record and, nominally, in the archaeological inventory.