What was once a rath, a type of circular earthen enclosure used as a farmstead in early medieval Ireland, now survives only as a faint scarp on the southern side of a pasture field. The enclosure itself, roughly thirty metres in diameter, has been levelled, its banks absorbed back into the agricultural landscape that eventually erased it.

The site appears on Ordnance Survey six-inch maps from 1842, 1904, and 1937, each time rendered as a hachured circle, the standard cartographic shorthand for a raised or embanked enclosure. The fact that it appears consistently across all three editions suggests it was still at least partially visible well into the twentieth century, even as it was gradually being reduced. By 1934, when a researcher named Bowman recorded it, the fort at Knockastuckane was one of five such levelled or partially levelled single-ramparted raths noted on land belonging to a Mr Leader in the area. The cluster of five, all of them in a similar state of loss, points to sustained agricultural pressure on what was once a landscape with a meaningful density of early settlement.