It cannot be seen by walking the ground; it appears only from above, as cropmarks, the differential growth of vegetation over buried features that reveals, in the right season and the right light, the ghost of an earlier landscape beneath the modern fields. What those marks outline is a large subrectangular enclosure, its geometry only tentatively legible, belonging to a period of occupation that has left no standing monument and no obvious name.

Cropmarks form when buried walls, ditches, or compacted surfaces affect how deeply roots can grow, causing crops or grass above them to ripen, yellow, or thrive unevenly. Seen from aerial photographs, this effect can trace entire enclosures that have been ploughed flat or simply absorbed into later land use over centuries. At Conna, the pattern is complex enough to resist easy reading. A circular cropmark abuts the external south-western corner of the main enclosure, and a smaller circular mark sits just inside the southern edge, internally. In the north-eastern quadrant there appear to be further internal subdivisions, possibly including a third small circular feature, though the overlapping signals are difficult to untangle. Circular enclosures of this kind, appearing alongside or within larger rectilinear boundaries, are commonly associated with earlier settlement activity in Ireland, though without excavation the date and function here remain open questions. The proximity to Conna Castle, a medieval tower house, adds another layer; the castle may have been built within or near a landscape already long organised and inhabited.

There is nothing to see at ground level, and the site is not marked or interpreted for visitors. The enclosure exists, for now, as a pattern readable only in archives and aerial records, waiting for the kind of scrutiny that would give its faint geometry a clearer meaning.