That later wall, probably laid down during post-medieval agricultural reorganisation, overlies the original drystone construction from the south-west, continuing through the west and round to the north-west, effectively erasing a portion of the cashel's circuit.

What survives beneath and around it is a cashel, a form of ringfort built from dry-laid stone rather than earthen banks and ditches, roughly circular in plan and measuring approximately 44.5 metres in diameter. Cashels of this type are generally associated with early medieval settlement in Ireland, typically dating from somewhere between the sixth and twelfth centuries, and they functioned as enclosed farmsteads, protecting a household and its livestock. This one sits in Mausrevagh in north County Galway, around 180 metres south-west of a separate enclosure, suggesting the wider landscape once held a cluster of such features. The interior is now densely overgrown, which both obscures what might remain inside and, in its own way, preserves it from further disturbance.