The word killeen, embedded in the townland name itself, signals this use directly. Cilliní were informal burial grounds used from medieval times well into the twentieth century; because unbaptised infants were considered unable to enter consecrated ground under Catholic Church practice, families interred them quietly in liminal spaces, old ruins, or earthworks already freighted with a sense of otherworldliness. What makes Killeenrevagh unusual is the structure they chose: a rath, an earthen ringfort of early medieval origin, its interior enclosed by a low circular bank and internal scarp.

The rath does not appear as a burial ground on the Ordnance Survey six-inch map of 1838, but by the 1930 edition it is clearly marked as one, suggesting the practice was established or at least formalised in the intervening decades. Inside the western half of the rath's level interior, simple uninscribed stone markers sit low in the ground, their arrangement giving an initial impression of randomness. Look more carefully, though, and clusters of close-set stones resolve into rough rows, aligned broadly north to south or north-northwest to south-southeast. Some of these rows appear to follow the line of older cultivation ridges that cross the rath's floor, which means the burials may have been placed deliberately in relation to the existing contours of the land. Just outside the rath, at the foot of the northwestern scarp, a shallow depression roughly five metres by four metres is defined by a low sod-covered rise on one side and a faint scarp on the other. A few stones push up through the turf here, and a single large flat slab lies on the northern edge; these, too, may mark graves, quietly extending the burial ground beyond the ringfort's boundary.