This is a rath, the most common monument type in the Irish landscape, a circular or oval enclosure formed by an earthen bank and an outer ditch, known as a fosse, where early medieval farming families lived and kept their livestock. Thousands survive across Ireland in varying states of repair, and this one at Edmondstown is a particularly instructive example of how such sites endure even when they have been considerably knocked about.

The enclosure measures roughly 33 metres west-northwest to east-southeast and just over 28 metres on its shorter axis, making it a modest but typical example of the form. It was recorded on the revised 1913 edition of the Ordnance Survey 25-inch map as an oval earthwork open to the north, and a more detailed survey carried out between 1970 and 1972 found the bank had been quarried away along its northern and north-eastern arc, with further gaps cut through at the south-east and south-west. Only the western stretch of the fosse remained clearly visible at that point. The interior, which slopes gently toward the north, had itself been quarried within its northern quadrant, and the ground outside the monument from the south-east round to the south-west bears quarry holes and more recent field banks, suggesting the site has served as a convenient source of material over a long period. Where the original entrance once stood is no longer clear, though the northern arc, before it was removed, may have been the most likely location.