Scattered stones breaking the surface of that band suggest what lies just beneath, the flattened remains of a wall that has been pressed almost entirely back into the soil.

The feature was noticed during a site inspection in August 1980, when surveyors visiting Kilcloony Castle and its bawn, the defended courtyard typical of Irish tower-house complexes, observed the telltale shift in vegetation that often betrays buried masonry. An aerial photograph taken in July 1967 shows it clearly, meaning the cropmark had been quietly legible for at least thirteen years before anyone formally noted it. The leading interpretation is that this was an outer enclosure wall surrounding the castle, an additional ring of defence beyond the bawn itself. A secondary possibility, that it belongs instead to the associated field system in the area, has not been ruled out, and the two explanations are not necessarily mutually exclusive. Outer enclosures of this kind, sometimes called bawns in a broader sense, were a practical feature of late medieval and early modern tower-house settlements in Connacht, providing a defended space for livestock and supplies as well as for the castle's occupants.