The enclosure measures roughly 42 metres east to west and 40 metres north to south, defined by an earthen bank that still rises about a metre above the interior ground level. A shallow external fosse, the ditch that would originally have reinforced the bank's defensive or territorial effect, runs around the outside. The entrance, 3.8 metres wide, faces to the south-east, a common enough orientation among Irish ringforts and one that tends to catch the morning sun.

Ringforts of this type, known in Irish as raths, are among the most numerous archaeological monuments in the Irish landscape, with tens of thousands recorded across the island. Most date from the early medieval period, roughly the fifth to the twelfth centuries, and they functioned primarily as enclosed farmsteads rather than military fortifications. A single family or extended household would have lived and worked within the bank, keeping livestock secure and marking out their claim to the land. What makes the Lackanastooka example quietly interesting is a low oval mound sitting inside the enclosure, measuring 16 metres north to south and 12 metres east to west, rising only about 0.4 metres above the surrounding ground. Interior mounds of this kind can represent the collapsed remains of a structure, a souterrain entrance, or earlier activity on the site predating the rath itself, though without excavation it is impossible to say what lies beneath.