The site at Ballyinsheen Beg sits in undulating ground on karstic limestone, that distinctively pitted and fissured rock characteristic of the Burren region, overlooked by a ridge to the west. What makes it quietly strange is the way the enclosure has been assembled, almost accidentally, from different materials over time: part earthen bank, part natural scarp, part curving stone field boundary, all conspiring together to trace an almost circular outline roughly fourteen metres across.

A rath is an earthen ringfort, the kind of enclosed farmstead that was built across Ireland in enormous numbers during the early medieval period, roughly between the fifth and twelfth centuries. Most were home to a single farming family and their livestock, the enclosing bank providing both a degree of security and a marker of status. The example at Ballyinsheen Beg is modest in scale, its internal bank rising only about twenty centimetres above the interior ground surface, though it stands nearer three quarters of a metre on the outside. More dramatically, a natural scarp along the western and northern arc climbs to about 1.8 metres, doing much of the defensive work that an earthen bank would have done elsewhere. A large limestone slab is visible at the south-southwest, and a few other stones project along the perimeter, though there is no surviving evidence of a stone revetment facing the bank. The site sits within a broader multiperiod field system, meaning people were organising this landscape across several different eras, and a low, collapsed, grass-covered field wall runs across the northern half of the interior, threading out into the surrounding fields as if the later agricultural world simply moved straight through the older one without pausing to acknowledge it.