Barrows appear in the Irish landscape as low circular mounds. These are sometimes referred to as tumuli but the term barrow is dominant in modern usage. Barrows are burial mounds and can hold single or multiple burials, or in some instances act as a focus for cemeteries. Excavated examples date from the late Neolithic to the Iron Age although they are more numerous in the Bronze Age. In general they measure between 10m and 25m in diameter (32ft to 82ft) but larger and smaller examples have been identified.
Construction usually involved excavating a circular ditch, normally with an entrance, around a central burial or group of burials. Cremation was the normal form of burial rite although inhumation was also practiced. In some cases burials were placed in simple earth cut graves while elsewhere a stone box, or cist, was constructed to entomb the burial. The up cast from the ditch was piled up in the centre to form the mound. In some instances the ditch can still be detected as an earthwork surrounding this mound. Large numbers of these monuments have been identified in recent years in Ireland in advance of road construction. In most cases they have been ploughed flat over the millennia, with only the ditch and deeper burials surviving.
Considering the effort required for their construction it is generally considered that barrows represent the final resting place of the upper echelons of ancient Irish society. In some instances the inter-relationship between barrows of different sizes and adjacent burials with no covering barrow may reflect the social hierarchy of the interred population. Numerous excavations have recovered evidence for the re-use of these monuments over significant periods, sometimes several centuries, which may indicate that they served as tribal burial grounds. Within this context the sites of barrows may have been used for ritual purposes beyond burial, possibly linked to ancestral memories and rites.