That is the entire story of the cist at Johnstown, and it is a quietly melancholy one. A cist is a small coffin-like box assembled from flat slabs, used in prehistoric Ireland typically for single inhumation or cremation burials. The Johnstown example was rectangular, measuring over 1.1 metres in length and 0.75 metres wide, with its long axis oriented roughly north-northeast to south-southwest. When quarry workers accidentally cut into the face of the sand ridge in 1968, they found it already badly compromised: only two stones remained standing on the west side, a low end-stone survived at the north, a single slab held on at the east, and the south end had already collapsed entirely.

The ridge on which it sat was, or had once been, the site of a windmill, which places this burial in a landscape that had already seen centuries of human modification before anyone thought to record what lay beneath it. What the cist originally contained is unknown. The interior was empty when examined, but the north end told a more complicated story: at some earlier point, a pit had been dug into it from above and subsequently backfilled with small rounded stones mixed with animal bones. Whether that disturbance was ancient or relatively recent, deliberate or incidental, was never established. The animal bones offered no obvious explanation. After the cist was recorded, quarrying continued and the structure was destroyed completely. Nothing survives at the site today.