A slight rise in the ground, barely a metre high, traces a near-perfect circle across the slope, and what appears to be a natural undulation is in fact the remains of an enclosure that has been standing, in some form, for over a thousand years.

This is a rath, the most common type of ringfort in Ireland, typically constructed during the early medieval period as a defended farmstead for a single family or small settlement. The Gubbeen example measures roughly 32 metres north to south and 29 metres east to west, enclosed by an earthen bank with an external fosse, a defensive ditch, running from the north around to the south-southeast, reaching nearly a metre in depth. The western face of the bank has been reinforced with stone, which suggests either a concern for that particular exposure or, more practically, that suitable stone was available nearby and incorporated into the structure at some point in its life. What makes the interior especially interesting is that cultivation ridges, the raised furrows associated with pre-modern tillage, run north to south across it. This means that at some point after the ringfort ceased to function as an enclosure, and possibly long after, someone ploughed the ground inside it, leaving the land surface layered with at least two distinct phases of use.