What makes the mound quietly unsettling is not what remains but what was taken. In 1792, local people building cottages near Castlepollard looked at this ancient burial monument and saw, quite practically, a convenient supply of rubble stone. Within months, the mound had been partially stripped and the burial chamber beneath it opened.

The chamber they exposed was a cist, a type of prehistoric stone-lined grave, wedge-shaped in plan, tapering to a point at its southern end, and constructed from perhaps seven or nine flagstones set upright on edge and covered with flat lintels. Inside, they found human remains. A letter written in 1793 by a William Chapman to the antiquarian Austin Cooper, later published by Liam Price in 1942, preserves a remarkable account of the episode. Chapman reported that four or five skeletons had been recovered from the chamber, though the skulls and most of the bones were quickly carried away by the people who found them. One thigh bone he noted as being only fifteen inches, roughly 38 centimetres, in length. He also recorded that the mound as it stood was composed of stones ranging from fist-sized to considerably larger, the whole covered by a layer of gravel and earth roughly three feet deep, with a circumference at the base of around ninety yards and an original height of approximately thirty feet. That was the mound in 1792; by 1793, the disturbed cairn material had already subsided back over the cist, sealing it again, and Chapman noted it was no longer accessible. The mound visible today, measuring around thirty metres at the base and nineteen across the summit, is considerably reduced from those eighteenth-century dimensions, a quieter shape in the landscape than it once was.