The enclosure is roughly 36 metres along its longer axis and 23 metres across, with an outer fosse, essentially a shallow surrounding ditch, adding to its overall footprint. That the townland boundary between Castleworkhouse and its neighbour runs along the enclosure's eastern edge is suggestive in itself; old administrative lines in Ireland frequently followed ancient earthworks, which were already landmarks when later boundaries were being drawn.

An embanked enclosure of this kind belongs to a broad category of earthwork found across Ireland, their precise functions still debated. Some enclosed early medieval settlements, others served ceremonial or agricultural purposes, and distinguishing between them often depends on excavation rather than surface survey alone. Here, the bank varies in height, rising to around two metres on the southern side while remaining considerably lower to the north, which points to either deliberate design or differential preservation over the centuries. There is an entrance gap on the north-western side, around 5.5 metres wide, though whether this was the original point of entry or a later break in the bank is unclear. That uncertainty is itself part of what makes the site interesting; it has been altered or interpreted and re-altered by time, and it does not give up its sequence easily.