That small detail gives the site an unexpected legibility: you can still read, in rough outline, how people once moved in and out of this enclosure.

The earthwork at Ballydonnellan is a rath, the most common type of ringfort in Ireland, typically a roughly circular area enclosed by an earthen bank and external ditch, used as a farmstead during the early medieval period, broadly between the fifth and twelfth centuries. This example is subcircular rather than perfectly round, measuring 36.2 metres east to west and 30.5 metres north to south. The enclosing elements vary around the circuit: a proper raised bank runs from the north around to the north-east, and from the east through the south to the west, while elsewhere the boundary is formed by a scarp, a steep slope cut into or shaped from the ground rather than built up as a mound. An external fosse, the ditch that would have reinforced the bank as both a physical and symbolic barrier, survives along a large arc from south-south-west through west to north-north-east. The site sits approximately 200 metres south-west of a recorded castle or tower-house site, a proximity that hints at a landscape used and reused across many centuries. Quarrying has disturbed the northern section of the enclosure, which accounts for some of what is now missing from that part of the circuit.