What exists here is known only because a camera mounted in an aircraft happened to pass overhead in July 1989 and captured something the soil had been quietly holding onto: a cropmark, the faint but legible shadow of a rectangular enclosure roughly 50 metres east to west and 30 metres north to south, pressed into the earth and invisible to anyone standing in the field itself.

Cropmarks form when buried features, ditches, walls, or pits, affect how crops or grass grow above them. A filled-in ditch retains more moisture, encouraging lusher growth; a buried wall does the opposite. From altitude, these differences in colour and height become readable as outlines of structures that have long since vanished from the surface. At Conva, the cropmark reveals what was once a fosse, a defensive or boundary ditch, enclosing a rectangular area. Running outward from the southern side of that enclosure are further faint linear marks, interpreted as the remains of a levelled field fence, extending east and west into the surrounding ground. What purpose the enclosure served, and when it was built, the aerial evidence alone cannot say. What it does confirm is that this part of north Cork was once organised and managed in ways that left their imprint deep enough to survive centuries of farming. Adding to the picture, a cluster of related enclosures and pits lies approximately 150 metres to the north-east, suggesting this was not an isolated feature but part of a broader pattern of settlement or land use in the area.