This ancient ringfort at Bun Na Toinne survives only as a short curved section of stone wall, now grass-grown and weathered by centuries of Atlantic winds. The remaining arc suggests the structure was originally circular, measuring approximately 15 metres in diameter; typical dimensions for a modest farmstead of its type.

The wall itself stands just 40 centimetres high and spreads between 3 to 4 metres wide, indicating it has collapsed and spread considerably from its original form. What makes this ruin particularly interesting is the visible remnants of stone facing on the interior surface, showing the care with which these structures were originally built. The interior ground level sits slightly lower than the surrounding landscape, a common feature of cashels that helped provide shelter from the elements whilst also creating a defined, defensible space for the inhabitants and their livestock.

Though only this small section remains, the cashel would have once been home to a farming family during the early medieval period, roughly between the 5th and 12th centuries. These stone-built ringforts were the Irish equivalent of fortified farmsteads, serving as both homes and defensive structures for rural communities. The proximity to Lough Swilly would have provided the inhabitants with access to both marine resources and fertile grazing land, making this an ideal location for settlement despite its now lonely and fragmentary state.