There is no signage, no viewing platform, and the cattle that graze here have done their own quiet editing of the site over the years, pushing through the encircling bank at three separate points until the gaps look almost deliberate. This is a rath, the Irish term for a ringfort, the most common monument type in the Irish landscape. Ringforts are roughly circular enclosures defined by earthen banks, and they were built predominantly during the early medieval period, functioning as farmsteads and defended family settlements. Thousands survive across the country, though many are far less legible than they once were.

The Ballynagaul example is modest in scale but structurally interesting. The main enclosure measures approximately twenty-three metres in diameter, enclosed by a flat-topped earthen bank that stands about one metre high on the interior side and two metres on the exterior, with a width of two metres at the top. What makes it slightly more complex is the presence of a concentric outer bank running from the north-west around to the north-east, lower and broader than the inner one, standing roughly forty centimetres high and eight metres wide. A ringfort with more than one encircling bank is sometimes referred to as a multivallate fort, a feature occasionally associated with higher-status occupants, though it would be too much to read great significance into that detail here without further investigation. The site was recorded and compiled by Denis Power, with notes uploaded in August 2011.

The interior is largely level under pasture, with some unevenness at the northern and southern edges. Dense overgrowth obscures the inner bank at both those ends, and the vegetation spills inward, making the full circuit harder to trace on the ground than the dimensions might suggest. The breaks in the bank at the north-north-west, north-east, and south-east are the work of cattle rather than any historical event. Visiting in late summer or early autumn, when growth has peaked but visibility is still reasonable, gives the best sense of the earthworks. The marshy quality of the surrounding pasture means the ground can be soft underfoot at most times of year, so appropriate footwear is worth thinking about before approaching across the fields.