These unremarkable-looking depressions are thought to mark the roof of a collapsed souterrain chamber; an underground stone-lined passage or cell, typically built during the early medieval period and associated with the raths, or enclosed farmsteads, that were once a common feature of the Irish countryside. What makes this particular site quietly interesting is not what is visible but what is not: most of the structure has effectively vanished beneath the surface.

A local correspondent writing in 1939 described the rath as having underground chambers that connected to a second souterrain on the eastern side of a nearby railway line. That second passage appears to be the same feature recorded in the 1940s as a blocked entrance to a souterrain sitting in the centre of what the source calls an "old fort", which is to say the same rath. Between the two accounts, separated by only a few years, the picture that emerges is of a more extensive underground system than the surface today would suggest, one that was already partially inaccessible by the time anyone thought to write it down. The railway, presumably laid in the intervening decades before the 1939 account, effectively cut across the landscape and may have contributed to whatever collapse or blocking had occurred.