No earthwork rises from the ground, no stone protrudes, no hollow hints at what lies beneath. The only reason anyone knows it is there at all is that a proposal for a solar farm triggered a geophysical survey in 2017, and the instruments picked up what the eye cannot see.

The enclosure measures approximately 50 metres on its northeast to southwest axis and around 40 metres across. Geophysics, which uses instruments to detect anomalies in the soil without breaking the surface, revealed a shape that is not quite regular: the northern and western sides run straight, while the southern and southeastern sides curve into a more typical rounded form. There appears to be a possible entrance in the southeast quadrant, and another possible break at the northwest angle, though neither shows a definitive gap in the enclosing element. A partial outer boundary runs roughly parallel to the north and south sides but does not continue around to the west, suggesting either an incomplete double enclosure or one that has been lost on that side. Most intriguing are two roughly parallel linear features inside the enclosure at its eastern end, running northward from the southern side but stopping short of the northern edge. Their function is unknown. The eastern edge of the enclosure itself has been cut across by a later field boundary, the kind of quiet erasure that happens over centuries of farming. Ballyconra is not alone in this; the same geophysical surveys identified at least ten other enclosures in the immediate vicinity, clustering together in the flat lowland in a way that suggests the area was once considerably busier than its present pastoral calm implies.