The site is a rath, the most common type of early medieval ringfort in Ireland, typically a circular earthen bank enclosing a farmstead or high-status dwelling. This one has been levelled so thoroughly that it takes a careful eye to detect it at all, yet the outline persists: a roughly circular area measuring about 31.5 metres northwest to southeast and 34.7 metres northeast to southwest, betrayed on the southwestern half by the faintest trace of a scarp and on the northeastern half by a barely perceptible undulation in the ground.

The enclosure was still legible when the Ordnance Survey produced its six-inch map in 1838, recorded there as a circular embanked feature of between 30 and 35 metres in diameter. By the time the survey was revised in 1931, it had vanished from the cartographic record entirely, suggesting the levelling occurred in the intervening decades, most likely as agricultural improvement cleared whatever earthwork remained. The site sits on a low ridge with open views to the south and northwest, the ground dropping away to the southwest towards flat, damp pasture. What is quietly remarkable about Lisbaun is that this single, nearly invisible rath is not an isolated survival but one node in a tight cluster: four further raths lie within 255 metres, one to the west, one to the north, one to the east, and one to the south. The density points to a landscape that was once thoroughly settled and organised, even if little of that organisation now survives above ground.