This one barely announces itself at all. At Ballynamona in County Cork, the only evidence of an enclosure roughly 45 metres across is a cropmark, the faint ghostly outline left in a field of growing grain when buried features beneath the soil cause uneven growth above them. In this case, the feature is a fosse, a defensive or boundary ditch, describing an almost complete circle. Without an aeroplane and a camera, it would be invisible entirely.

The enclosure came to light in an aerial photograph taken in July 1989 as part of a systematic survey of the Irish landscape. Cropmarks of this kind tend to show best in dry summers, when shallow-rooted crops over buried ditches, which retain more moisture, grow fractionally taller or greener than the surrounding field, producing a pattern legible only from altitude. What the photograph revealed was a roughly circular enclosed space, a form common in early medieval Ireland, where such enclosures served as farmsteads, territorial markers, or places of status and sometimes defence. A ringfort, a related type of enclosed settlement typically defined by earthen banks, sits approximately 50 metres to the south-west, suggesting this corner of North Cork was meaningfully occupied at some point in the past, though whether the two features are contemporary remains unknown.