The hill is thought to have been the location of an extensive prehistoric cemetery, its dead interred in pit and cist graves, a cist being a small stone-lined box cut into the ground to receive a body or cremated remains. The burials were accompanied by pottery characteristic of the Bronze Age, including bowl and vase food vessels and cordoned urns, vessel types typically placed with the dead during the second millennium BC. Despite the scale suggested by the historical record, the surface today is unbroken farmland, cleared and improved over generations until every trace has gone.

What makes the site stranger still is the suggestion that the cemetery was never simply an open hillside of graves. References going back to an 1853 paper in the Journal of the Royal Society of Antiquaries of Ireland mention levelled entrenchments, earthworks, and what was recorded as the site of an old rath, a circular enclosed settlement. This hints that Ballon Hill may once have carried a ringfort or a ring-barrow, a low circular earthen mound of the kind often raised over Bronze Age burials, linking the funerary complex to some form of enclosure or boundary. By the mid-twentieth century, further scholarship had assembled these scattered references into a picture of a hilltop that had once been quite deliberately shaped around its dead, though even then the earthworks were described as largely levelled. In 2005, the archaeologist Coilin Ó Drisceoil carried out test trenching across the area and found nothing of archaeological significance, which does not mean the burials have been destroyed, only that they did not happen to fall within the trenches, or that whatever remains lies deeper or elsewhere on the hill.