On a high pasture field in Tipperkevin, County Kildare, the ground holds a secret that is almost impossible to see from the surface. Only when aerial imagery is studied does a broad, curving arc begin to resolve itself, the faint signature of a ditch tracing roughly three-quarters of a circle across the hillside. The feature, approximately 110 metres in diameter, is visible as a cropmark on satellite orthoimages from the south, west, and northern arcs, suggesting what may be the remains of a hilltop enclosure, a class of monument in which a ditch and presumably an accompanying bank once defined a large circular space on elevated ground.

Cropmarks form when buried ditches or pits, which retain moisture differently from the surrounding subsoil, cause the vegetation or crops above them to grow in subtly distinct patterns, patterns that become legible from above, particularly during dry spells. The enclosure at Tipperkevin sits on ground that commands good views in all directions, a location consistent with the siting of prehistoric or early medieval enclosures across Ireland, where prominence in the landscape often seems to have mattered as much as defensibility. The eastern edge of the suspected enclosure aligns with a north-south field boundary that also marks the townland boundary of Glebe West, a coincidence of lines old and older that is not uncommon in Irish landscapes, where ancient features frequently got absorbed into later administrative and agricultural divisions.