It measures roughly 24 metres north to south, 22 metres east to west, and still rises to a height of 3.5 metres, which makes it a substantial monument even in its present, slightly disturbed state. The northern side shows evidence of stone removal at some point, a reminder that cairns like this one have long been treated as a convenient quarry by those who needed building material and had no reason to consider what lay beneath.

A cairn of this type is essentially a mound of loose stones, raised by human hands rather than by geological accident. In an Irish prehistoric context, such monuments are most commonly funerary in origin, sometimes covering a burial chamber or cist, though they also served as territorial markers or places of assembly. The choice of a hilltop is characteristic: height conferred visibility in both directions, making the structure legible across a wide territory and placing the dead, or the commemorated, in a position of symbolic dominance over the surrounding land. Without excavation it is impossible to say what, if anything, survives beneath the surface at Ballydague, but the scale of the cairn suggests it was built with considerable communal effort and intention.