In a level pasture in County Kildare, a narrow ridge of glacially deposited gravel and sand, known as an esker, carries eight prehistoric burial mounds along its spine. The esker at Barrettstown is short and modest in height, its upper surface fairly level and largely given over to nettles, yet it holds an unusually concentrated arrangement of funerary monuments that speaks to deliberate, repeated use of this particular landform over what was likely a considerable stretch of prehistory.

Six of the eight barrows run in a north-south line along the northern end of the esker, sitting close enough together to be considered contiguous. Unusually, these six are enclosed within a single earthwork that girdles the lower slopes of the esker itself, drawing a boundary around the whole cluster. Two further barrows lie approximately 48 metres to the south, slightly downslope and outside this enclosure. The most southerly of the group is a circular mound roughly 13.3 metres in diameter, defined by a steep scarp nearly two metres high and ringed on its south-eastern to south-western arc by an outer fosse, a shallow ditch about 1.2 metres wide and 0.8 metres deep. Barrows of this kind are prehistoric burial monuments, typically earthen mounds raised over the remains of the dead, and they appear across Ireland in a variety of forms from the Neolithic through the Bronze Age. The esker itself is a product of the last Ice Age, formed from sediments deposited by meltwater rivers flowing beneath glaciers, and the evidence of extensive sand and gravel extraction immediately to the north and east of the site suggests the landform has been significantly altered in the modern period, making the survival of the mounds on the ridge itself all the more notable.