Aerial imagery has revealed a circular cropmark roughly forty metres in diameter, the outline of an ancient enclosure that has long since disappeared from the surface but persists as a ghost in the ground beneath. Cropmarks form when buried features, such as ditches or banks, affect the moisture and nutrient content of the soil above them, causing the crops growing overhead to ripen or wilt at slightly different rates. From the air, those subtle differences in colour and height trace the shapes of structures that would otherwise be invisible.

The enclosure at Subulter was identified from satellite imagery, with its circular ditch defining what was most likely a ring enclosure, a category of monument found widely across Ireland and typically associated with the early medieval period, though such features can span a broad range of dates. A ditch of this kind would originally have surrounded a farmstead or enclosed a space with social or ceremonial significance. At around forty metres across, it falls within the range commonly seen for small rural enclosures. The site was brought to attention by Jean-Charles Caillère, whose observation through commercial mapping tools added it to the body of known but unexcavated sites in the Cork landscape.

The enclosure is not visible at ground level and there is nothing to mark it in the field. It exists, for now, only as a faint signal read from above, waiting on whatever future investigation the soil might eventually yield.