The cliff itself, between nine and eighteen metres high and described as practically perpendicular, does the work that a second enclosing wall would otherwise have to do. A cashel, which is a stone-walled enclosure of early medieval type, typically built without mortar, this one measures roughly 62 metres by 50 metres internally, and its curving man-made wall of unworked flags and boulders runs from northwest to south-southeast, meeting the cliff edge where a modern field wall now marks the boundary. The result is a fort that is genuinely difficult to read from within; the interior slopes southward and is very uneven, and what might once have been an entrance has been obscured or destroyed by later gaps in the stonework.

When the antiquarian Thomas Johnson Westropp visited in 1901, he found the structure massive and reasonably intact, noting a half-moon plan and a wall built in two distinct sections from large, roughly dressed slabs. He also observed a recess in the inner wall-face at the northeast, which he thought may have served as a step arrangement for reaching an internal terrace, a feature that is still visible today at around 1.2 metres wide. The fort shares its name with the townland, recorded in 1660 as Lisniceada, and identified on later maps as Lios Mac Síoda, translated by James Frost in 1893 as Mac Sheedy's homestead. The slight divergence between the 1660 spelling and the modern Irish form suggests the name has shifted over centuries of anglicisation and re-Gaelicisation. The site sits within a multiperiod field system that speaks to long and layered use of this limestone plateau, and the substantial cashel known as Caherfeenagh lies about 200 metres to the northwest, with a hut site roughly 100 metres to the east-northeast, suggesting this was once a busy and organised landscape rather than a lonely outpost on a cliff.