It is a cillín, the Irish term for an unconsecrated burial ground used historically for unbaptised infants and others who, under Catholic Church practice, were excluded from burial in consecrated ground. These sites are scattered across the Irish landscape in their hundreds, often unmarked on any map, their small graves absorbed quietly into the countryside over generations.

The site at Tullaher sits on a south-facing slope at the southern end of a ridge, roughly circular in shape and measuring about seventeen metres north to south and eighteen metres east to west. At its centre is a slightly elevated area, around five metres in diameter, which is heavily overgrown. Within this central zone, three stone grave markers have been recorded, one still standing upright at a height of no more than forty centimetres, the other two smaller and lower. Across the rest of the mound, further very low stone markers lie beneath the grass, their presence detectable but their surfaces largely obscured. The modesty of these markers is characteristic of cillíns, where formal commemoration was rarely encouraged and sometimes actively discouraged, leaving families to mark graves with whatever stones came to hand.

The physical form of the site, a slightly raised circular platform standing apart from the working land around it, is typical of how such burial grounds were maintained at a quiet remove from everyday activity. The boggy, rush-filled ground surrounding it has likely helped preserve the mound from agricultural disturbance, though the heavy overgrowth of the central area means much of what lies beneath remains unexamined.