What remains here is a subrectangular enclosure, roughly 31 metres east to west and 29.5 metres north to south, defined by an earthen bank so worn down by time and weather that it barely announces itself against the surrounding grassland. It is the kind of site that rewards slow attention rather than a quick glance.

Enclosures of this type are a recurring feature of the Irish countryside, earthworks that once defined a bounded space, whether for settlement, agriculture, or ritual purposes. They were typically formed by raising a bank of soil and stone, often with an accompanying fosse, or ditch, dug just outside it. At Lisnageeragh, faint traces of that external fosse can still be made out along the western, northern, and north-eastern sides, which suggests the original structure followed a fairly standard arrangement, even if centuries of land use have reduced it to something close to invisibility. The hilltop position is notable; elevated ground was frequently chosen for enclosures in early medieval Ireland, for reasons that may have combined practical oversight of the surrounding landscape with a degree of social display.