It measures roughly 12.5 metres across, defined by an earthen bank that rises only 0.15 metres above the enclosed ground, with a shallow surrounding ditch, between 0.1 and 0.25 metres deep, that holds water and has filled in over time with rushes. At that scale and with so little elevation, it reads less as a monument than as a slight irregularity in the ground, the kind of thing a farmer or a walker might cross without a second thought.

What makes the site genuinely interesting is what it might be. Researchers have noted its close similarity, in terms of size and overall form, to ring ditches and ring barrows recorded elsewhere in counties Limerick and Tipperary, as documented in a series of studies by Martin Doody published between 1993 and 2008. A ring barrow is a type of low prehistoric funerary monument, typically consisting of a circular bank and ditch enclosing a central area, often associated with burial. The earthwork at Ballynagoul fits that profile. Google Earth imagery from both 2006 and 2017 suggests a possible entrance on the western side. A field boundary clips the enclosure on its south-eastern edge, which complicates the picture slightly; that boundary is likely of more recent origin, though it predates 1840, since it does not appear on the first edition Ordnance Survey maps of the area. The site was compiled and documented by Dr Eugene Costello, with records updated as recently as March 2023.

The enclosure sits low enough that visiting without prior knowledge of its location would make it genuinely difficult to identify with confidence. Ground-level photographs, including a south-west facing view uploaded alongside the site record, give a better sense of the subtle topography than any description can. The wet ditch and rush growth are useful markers on the ground. Because the site is unexcavated and its prehistoric character remains provisional rather than confirmed, it occupies that quietly ambiguous category of earthworks, present and measurable, but not yet fully explained.