The structure at Caherlissakill measures roughly ten metres north to south and nine metres east to west, making it a fairly modest subcircular form. No entrance can be identified anywhere along its circuit, which is itself an oddity; most enclosures of this kind, whatever their purpose, show at least some trace of how people got in and out.

What survives is a wall reduced almost entirely to a grassed-over bank, though internal stone-facing is still visible along the north-western arc. More intriguing is a secondary wall in the south-western quadrant, dividing the interior, suggesting the space was at some point organised for a specific use rather than simply enclosed. The structure sits around four and a half metres to the north-east of the cashel, close enough to suggest a relationship with it, though what that relationship was remains unclear. Whoever built or used the cashel may have constructed this smaller enclosure as an ancillary space, and the internal division raises the possibility that it served as a house, though the evidence stops well short of confirming that.