A circular cropmark roughly thirty metres in diameter shows up on aerial imagery, the kind of ghostly outline that only becomes legible when you pull back far enough to see the whole picture. It is not visible from the road, not marked by any standing stone or interpretive panel. The only way most people will ever encounter it is by zooming into a satellite map and noticing that the grass is doing something slightly different in one particular spot.

Cropmarks form when buried structures, ditches, or pits affect the way plants grow above them. Soil that once filled an ancient ditch tends to retain more moisture, producing lusher, taller crops; a buried wall does the opposite. From ground level, the difference is imperceptible. From the air, especially during a dry summer when contrasts are sharpest, circular enclosures that have been invisible for centuries can suddenly reappear. The Flacketstown example was captured in an orthoimage taken on 24 June 2018, a date that likely fell during a period of dry weather when the underlying feature expressed itself most clearly through the crop. It was also independently visible on Apple Maps imagery. The record was compiled by Caimin O'Brien, drawing on details provided by Jean-Charles Caillère, and uploaded to the record in November 2021. What the enclosure actually was, whether a ringfort, a burial monument, a ditched enclosure of some other function, remains unconfirmed; the shape alone is documented.

Because the feature exists only as a cropmark, there is nothing to visit in any conventional sense. The field itself is farmland, and the enclosure has no surface expression. The most useful approach is through the aerial platforms on which it was identified: Google Earth allows users to consult historical imagery layers and to find the June 2018 capture specifically. Looking in dry summers, when soil moisture differences are most pronounced, gives the best chance of seeing the mark clearly. For anyone interested in landscape archaeology, the exercise of finding it is itself instructive, a reminder that a great deal of what people built and dug across this island is still present beneath working fields, waiting for the right angle of light and the right dry week to briefly show itself again.