In the low-lying pastureland of Inch St. Lawrence North in County Limerick, a possible circular enclosure was detected not by any physical trace on the ground, but as a cropmark visible only from the air. When someone eventually walked out to look for it, there was nothing to see.

Cropmarks appear when buried features, ditches, walls, or pits, affect the growth of crops or grass above them. A filled-in ditch, for instance, retains more moisture than the surrounding soil, producing a slightly lusher or differently coloured strip of vegetation that can be invisible at ground level but legible from altitude. The enclosure here was identified from aerial photograph AP 4/3741, which appears to show the outline of a circular form, the kind of shape often associated with ringforts or early medieval settlement sites in Ireland. Ringforts, known in Irish as raths or lios, were typically enclosed farmsteads surrounded by one or more earthen banks and ditches, and circular enclosures of this type are among the most common archaeological features in the Irish landscape. Whether this particular cropmark represents something of that kind, or something older, or simply a trick of light and drainage, remains unresolved. Compiled by Denis Power and uploaded to the record in June 2013, the entry notes plainly that when the site was inspected, no evident trace of the enclosure could be found.

The location sits immediately south of a small river, in poorly-drained pasture, with open views to the south-east, south, and west. That waterlogged ground may itself be part of the reason the feature has left so little impression; wet, compacted soil does not always preserve the subtle differences in vegetation that make cropmarks legible on the ground. Visiting with any expectation of a visible monument would lead to disappointment. What remains here is more of an absence, a placeholder in the record for something that may yet be confirmed with different conditions, a dry summer, a different crop, or a future survey.