On a south-facing slope above the Ballyleary stream in County Cork, there is no earthwork to inspect, no enclosing bank or ditch, no aerial photograph showing a crop mark in a summer field. A farm shed now occupies the site, and the ground gives nothing away. What survives is the placename itself: Lissanisky, understood to mean "Fort of the Water", a linguistic fossil preserving the memory of a rath, a roughly circular earthen enclosure of the kind built across Ireland during the early medieval period, that has otherwise vanished entirely.

Writing in 1904, a historian named Healy noted that the rath "has completely disappeared", with part of its footprint already taken up by a residence, and described the defining feature that gave the place its name: a stream that ran through the fort itself. By 1918, however, P.H. Power was pointing to a different, still-standing lios nearby as the true name-giver, which introduces a small but genuine ambiguity into the record. A lios is simply the Irish word for an enclosed fortified dwelling, broadly synonymous with rath, and both terms tend to describe the same class of circular farmstead. Whether the vanished enclosure at Lissanisky or its surviving neighbour to the west gave the townland its name may never be settled with certainty. What the landscape around it does confirm is a pattern of early activity: another ringfort lies roughly 170 metres to the west, and several fulachta fiadh, the burnt mounds associated with prehistoric cooking or industrial use of heated water, have been recorded to the west and north-west of the site.

There is nothing to see at Lissanisky itself, and that, in a way, is the point. The fort is gone, the water still runs, and the name quietly carries the whole story.