The site at Ballynagrana is a ring barrow, a type of funerary enclosure in which a low central mound or platform is surrounded by a circular ditch and an outer earthen bank. Here, the whole structure measures just over three metres across its interior, and the enclosing fosse, the ditch cut around it, reaches no more than fifteen centimetres deep at its best-preserved arc. The outer bank is shallower still on its exterior face. It is, by any measure, a monument that has almost returned to the land.

The monument sits roughly 2.2 metres south of the natural scarp of an old water channel that once ran roughly east to west across the area. The surrounding ground undulates gently, shaped by that former water activity rather than by any human hand. There is a gap in the bank at the north-east, about 1.25 metres wide at its base, which may represent an original entrance or simply a point of later disturbance. The interior is fractionally lower than the surrounding ground level, sitting about seven centimetres below it, a subtle but telling inversion. Two related monuments lie very close by: another ring barrow just 0.9 metres to the north-east, and a ditch barrow approximately two metres to the east, suggesting that this spot was treated as a place of repeated or communal significance during prehistory. The site was first identified as a ring-ditch through aerial photography, the overhead view revealing the circular cropmark that ground-level observation had long failed to register.