It took an aerial photograph, taken during the Bruff aerial photographic survey in 1986, to bring it properly to light. What the survey image revealed, catalogued as Bruff 282 (AP 4/3658), was a ring-barrow, a type of funerary earthwork typically dating to the Bronze Age, consisting of a roughly circular central area enclosed by a ditch, known as a fosse, with an earthen bank raised on the outer edge. This particular example measures some 38 metres east to west, making it a substantial feature for something that remained effectively invisible to map-makers for centuries.

The monument sits on flat pasture in the townland of Ballyhobin, close to two townland boundaries. Its southern tip actually crosses into the neighbouring townland of Rathjordan, bisected by that boundary line, while the site itself lies 50 metres east of the boundary with Doonvullen Upper. A second ring-barrow, recorded separately, sits approximately 250 metres to the north, suggesting this corner of east Limerick may have held some significance in the prehistoric period, though the relationship between the two monuments remains unexplored in the available record. The Ballyhobin barrow was compiled into the Sites and Monuments Record by Edmond O'Donovan, with notes uploaded in September 2020.

The monument is not accessible as a formal heritage site, and because it was absent from historic maps, there are no old boundary markers or signposts to guide a visitor. It is, however, faintly visible on aerial imagery, appearing in Ordnance Survey orthoimages from 2005 to 2012, and clearly enough on Google Earth images taken in April 2006 and June 2018 that the circular fosse and outer bank can be made out against the surrounding pasture. The best approach for anyone curious about the site is through those aerial views before visiting, using the imagery to understand what the subtle ground-level traces actually represent. The low, grass-covered earthworks are the kind that reward patience and a low sun angle, when shadows pick out the slight differences in relief that mark the fosse and bank.