The visible evidence is ambiguous but suggestive: a large circular hollow roughly six metres across sits near the centre of the enclosure, and a fosse-like depression runs along the inside of the inner bank from east to south, dropping to about half a metre in depth. Either feature, or both, may mark the entrance or collapse point of a souterrain, an underground stone-lined passage of the kind commonly associated with early medieval ringforts and used variously for storage, refuge, or concealment. The oral memory of something beneath the ground has outlasted any certainty about what it actually is.

The fort itself sits on a prominent rise in undulating grassland in Cartron, North Galway, and would once have commanded a reasonable view of the surrounding landscape. It is a rath, the most common type of Irish ringfort, typically consisting of one or more earthen banks enclosing a circular or subcircular area of domestic or agricultural use. This one is subcircular in plan, measuring 39 metres north to south, and defined by two banks with an intervening fosse, the ditch that separates them. A gap of four metres at the southern side likely marks an original entrance. The monument is poorly preserved: a later field wall cuts across it at two points, no surface trace survives to the west of that wall, and much of the outer bank and fosse has disappeared, surviving only along the south-south-east to south-south-west arc. What remains is a partial, eroded outline, easier to read when you understand what you are looking at than when you encounter it cold.

The interior rises slightly toward the centre, where the low scarp and hollow are most visible. That central rise is characteristic of some raths and may reflect the accumulated remains of long-vanished structures, or simply the natural contour the original builders chose to occupy. The possible souterrain has been recorded separately in the site register, though its precise nature remains unconfirmed. It is the kind of place where the archaeology raises more questions than it settles, and where a piece of local knowledge, passed down without documentation, turns out to be the most interesting thing on the site.