What gives this particular enclosure away is not anything visible at eye level but rather a slight circular depression, roughly fifteen metres across, pressed into the turf. The site only fully reveals itself from the air, where an aerial photograph captured it as a cropmark, the faint but legible signature of a buried bank and an external fosse, or ditch, that once defined its perimeter.

Cropmarks form when buried features affect the moisture and nutrient content of the soil above them, causing the crops or grasses growing overhead to respond differently, greener and lusher over a ditch where organic matter accumulates, paler and thinner over a compacted bank or wall. This makes aerial photography one of the more reliable ways of locating low-lying or heavily eroded enclosures, particularly in improved agricultural land where ploughing and drainage have long since smoothed out surface relief. The enclosure at Ballygarrane fits a type well known across Cork and the broader Irish countryside, a small circular or subcircular form defined by a bank and ditch, most commonly associated with early medieval settlement, though without excavation a precise date and function remain open questions. Such enclosures are sometimes the remains of a ringfort, the farmstead of a farming family in the period roughly between the fifth and twelfth centuries, though they can also represent enclosures of earlier or later date, or serve purposes ranging from stock management to ceremonial use.