What gives it away is a single aerial photograph, which catches what ground-level observation entirely misses: the faint but legible outline of a ditch barrow, a circular prehistoric burial monument defined by a surrounding ditch rather than an upstanding earthen mound. The landscape around it is gently rolling farmland, and the site itself sits on flat pasture that offers no hint of what lies beneath.

Ditch barrows belong to a tradition of funerary monument-building that stretches back into prehistory across Ireland and Britain. Unlike the more familiar raised mounds, a ditch barrow is defined primarily by its encircling ditch, sometimes with only a low or barely perceptible internal mound, which means these monuments are especially vulnerable to centuries of cultivation, grazing, and erosion. The Ballaghgar example was identified through a Cambridge University Collection of Aerial Photography image catalogued as CUCAP ATC 73, and documented in the Archaeological Inventory of County Tipperary compiled by Jean Farrelly and Caimin O'Brien, published in 2002. Even at the time of that survey, the structure was classified only as a possible ditch barrow, the aerial evidence being suggestive rather than conclusive.