The ring barrow at Coolbreedeen is a raised circular earthwork, its interior measuring roughly 26 metres across, encircled by an external fosse, which is essentially a ditch dug to define and separate the monument from the surrounding land. What makes this site particularly interesting is the suggestion, visible in aerial imagery, that the original structure may not have stopped there at all.

The full extent of the monument only becomes apparent when you move beyond ground level. Analysis based on the 1897 Ordnance Survey 25-inch map, combined with Digital Globe orthophotos taken between 2011 and 2013 and a Google Earth image from June 2018, compiled by Edmond O'Donovan and uploaded to the record in July 2020, reveals what appear to be further concentric outer ditches beyond the visible fosse. If confirmed, this would make it a bivallate or even trivallate enclosure, meaning it originally had two or three surrounding ditches rather than one, potentially extending the full diameter to around 60 metres. Comparable multivallate enclosures in the county, including the site at Rathanny, have been attributed to the Bronze Age and interpreted as barrows or burial mounds. A similar triple-ditched barrow has also been recorded in the nearby townland of Ballyroe Lower, which suggests this part of Limerick may once have held a broader ceremonial or funerary landscape. A possible ringfort lies roughly 350 metres to the south-east, adding another layer of long use to this patch of ground.

The monument sits approximately 1.5 kilometres west of the Killeenagarriff River, in open pasture with no particular natural feature to draw the eye. Because the earthworks are low-lying and subtle at ground level, the outer ditches are difficult to read without prior knowledge of what to look for. The raised central area is the most legible feature on foot, and the outer concentric elements are far better appreciated through aerial images than in person. The land is agricultural, so any visit should be undertaken with care and appropriate landowner permission. The monument has no formal access or interpretation, and its significance is almost entirely contained within the archaeological record rather than the visible landscape.