This is a rath, the commonest form of early medieval settlement in Ireland, typically built between roughly the fifth and twelfth centuries as a defended farmstead for a single family or small community. A rath consists of a raised earthen bank enclosing a circular area, with a fosse, or external ditch, dug around its perimeter. At Kiltycahill, the enclosed area measures approximately twenty-two metres across, the surrounding bank running to nearly four metres wide, and the fosse beyond it to over four and a half metres. Modest figures, perhaps, but enough to mark a household boundary with some authority.

What makes this particular example quietly interesting is the degree to which the surrounding landscape has grown into it. Field boundary banks now run directly along the line of the old fosse to the east and south-east, and three separate boundaries connect to the rath bank itself at different points on the compass. The fosse has disappeared entirely along the north-east to north-west arc, and the bank is heavily worn and difficult to follow on its western and south-eastern sides. Where the original entrance once broke the circuit, there is now no trace. The interior, rather than being an open readable space, is densely choked with thorn bushes. It is a site that has been quietly parcelled into working farmland over the centuries, its geometry folded into a later system of enclosure without being entirely erased.