The site is invisible at ground level, leaving the pasture looking like any other unremarkable patch of the Irish countryside. The only evidence of its presence comes from above, where aerial photography reveals a ghostly circular cropmark roughly thirty metres in diameter, the faint signature of an ancient enclosure pressed into the soil beneath.

The cropmark traces the outline of a fosse, the defensive ditch that would once have surrounded a rath, the Irish term for a roughly circular earthwork enclosure used as a farmstead during the early medieval period, broadly between the fifth and twelfth centuries. Thousands of these structures once dotted the Irish landscape, and many survive as earthworks still visible to the eye. This one does not. Over centuries, the raised bank and the depression of the ditch have been smoothed away by ploughing, livestock, and time, until all that physically remains is a difference in the soil. In dry summer conditions, the crops or grasses rooted above that old ditch draw on slightly different moisture levels than the surrounding ground, and that variation registers from the air as a tonal difference, a ring emerging briefly from the green or gold before vanishing again with the season.