A partial cropmark, roughly 65 metres in diameter, shows up in aerial photography as a faint arc pressed into the landscape, the kind of ghostly geometry that only becomes legible from above, and even then only under the right conditions.

Cropmarks form when buried features, walls, ditches, or pits, affect how plants grow above them. Soil disturbed by an ancient ditch tends to retain more moisture, producing lusher, taller crops that read as darker lines when viewed from the air, particularly during dry summers when the contrast is most pronounced. The arc visible at Coola was captured in Google Earth aerial imagery from June 2018, and is tentatively identified as part of a circular enclosure. Enclosures of this general size are commonly associated with early medieval ringforts, the remains of farmsteads that once defined the Irish countryside in their thousands, though without excavation the date and function of this particular feature remain open questions. What can be said is that the diameter, approximately 65 metres, falls within the range typical of a substantial ringfort or possibly an earlier prehistoric enclosure.