The enclosure measures roughly thirty metres across, ringed by an earthen bank and a substantial external fosse, the term for a defensive ditch, that has, in places to the west, filled with standing water. The interior and banks are now heavily overgrown and effectively inaccessible, which means this particular rath has been left largely to itself, a quality that makes it easier, not harder, to imagine it as it once functioned.

A rath is an early medieval ringfort, typically dating from the first millennium AD, and thousands of them survive across Ireland in varying states of preservation. What makes the Liscullane example quietly interesting is a detail that only becomes visible when you look at old Ordnance Survey maps. Both the 1905 and 1936 six-inch editions show a stream running through the fosse itself, flowing roughly from the south-southwest to the north. This is not a coincidence of proximity; the water appears to have been directed into or along the ditch, a hydraulic arrangement that would have added a genuinely wet obstacle to what was already a formidable earthwork boundary. Whether this reflects an original design feature or a later adaptation of the landscape is not certain, but the maps document it clearly across at least three decades. To the east, field clearance material, stones and debris gathered from the surrounding farmland over generations, has been dumped onto the bank and into the fosse, the kind of incremental alteration that affects many such sites without anyone quite intending to alter history.