It is a ditch barrow, a type of prehistoric burial monument defined not by any dramatic height but by its form: a flattened mound enclosed by a shallow surrounding ditch, known as a fosse. This one measures seventeen metres across at its base, narrowing to ten metres at the top, with the fosse running about two metres wide around it. In places, that ditch still holds water, which gives the monument an oddly alive quality for something that may be thousands of years old.

Barrows in general are among the more quietly persistent features of the Irish landscape, raised over the dead during the Bronze Age or earlier, and often surviving simply because the ground around them continued to be farmed rather than built upon. The ditch barrow variant is less commonly discussed than the more imposing passage tombs or ring barrows, but it represents the same broad impulse: to mark a place of burial with a defined boundary between the world of the living and whatever lay beneath. What makes the Cashel example particularly worth noting is its immediate context. A mound barrow of a related but distinct type lies just twelve metres to the south-southwest, meaning the two monuments sit in close proximity in the same stretch of pasture, suggesting this corner of Sligo was treated as a place of some significance by the people who shaped it.