It has no name, no marker, and no entry in the standard cartographic record of Irish monuments. The only reason anyone knows it is there at all is that, under certain conditions, the grass above it grows differently from the grass around it, and that difference becomes visible from the air.

The site sits in reclaimed pasture in the townland of Coolnanoglagh, roughly 130 metres north of the boundary with Glenduff. What gives it away is a cropmark, a phenomenon where buried features such as ditches, walls, or pits affect soil moisture and nutrients in ways that alter the growth or colour of crops and grass above them. From ground level there may be nothing to see at all. From above, the outline resolves into a near-perfect circle approximately 30 metres in diameter. This particular mark was recorded on a Digital Globe orthoimage captured between 2011 and 2013, and again on a Google Earth image dated 29 March 2012. The record was compiled by Fiona Rooney and uploaded to the National Monuments Service database in November 2021. The monument has not been dated or formally classified beyond the broad category of earthwork, and it does not feature on Ordnance Survey Ireland's historic mapping layers, which means it either escaped earlier survey efforts or was simply not legible at ground level when those surveys were conducted.

Because the feature is a cropmark rather than a visible earthwork, visiting in the conventional sense is a complicated proposition. The field is ordinary reclaimed agricultural land, and there is no physical structure to observe from a gate or a roadside. The most revealing view remains aerial, which is largely what brought the site to attention in the first place. Anyone with a serious interest in the monument would do well to consult the National Monuments Service record directly, where the Google Earth orthoimage is referenced, and to note that cropmarks of this kind tend to be sharpest during dry summers when vegetation stress is most pronounced. The circular form, if it is a ring-ditch or the remnant of an enclosure of some kind, places it within a broad and ancient tradition of circular monument-building in Ireland, though without excavation, its age and purpose remain open questions.