They mark the graves of unbaptised infants, buried here across generations in a place that Catholic doctrine long excluded from consecrated ground. These informal cemeteries, known in Irish as cillíní, are found throughout Ireland, often tucked into older earthworks, field margins, or coastal edges. At Brees, the platform sits within a ringwork, a type of medieval enclosure defined by a raised bank and interior ditch, and that older landscape gives the site a particular quality of layering, one use folded quietly inside another.

The platform itself measures roughly 16 metres by 26 metres and occupies the south-western end of the ringwork interior, separated from the rest of the enclosure by a shallow depression along its northern arc. A scarp, essentially a stepped drop in ground level, defines the platform to the west and south-east, rising to about 1.3 metres at its highest point along the south-west. Stones protruding from the top of this scarp may be the remains of a kerb or low wall. The site does not appear on the Ordnance Survey six-inch map of 1838, but by the 1920 edition it is marked by name. It was first formally recorded by Knox in 1911 to 1912. According to local memory, burials continued here into the early 1950s, making this a place that remained in active, if unofficial, use well within living memory.