Measuring roughly twenty metres across, it leaves no trace on the surface of the ground, no raised bank, no hollow, no break in the grass. It exists, to all practical purposes, only from the air.

The enclosure sits on level ground at the edge of a steep drop into the Cookstown River valley, a position that would have made good practical sense to whoever constructed it, offering a natural boundary to the north while the enclosed area itself remained on flat, workable land. Circular enclosures of this kind are among the more common monument types in the Irish countryside, typically interpreted as the remnants of early medieval farmsteads, known as ringforts, where an earthen bank and ditch once defined a family's living space and offered some protection for livestock. Over centuries, ploughing can reduce such banks entirely, leaving nothing visible at the surface. What survives at Cookstown is detectable only as a cropmark, a phenomenon where buried features influence the growth of crops above them, causing subtle differences in colour and height that become legible in aerial photographs taken under the right conditions, usually during a dry summer when stressed vegetation betrays what lies beneath.