The enclosure measures approximately 35 metres on its longer axis and 25 metres across, defined by an earthen bank some five metres wide and rising nearly two metres on its outer face. Beyond the bank runs a fosse, the term for a defensive ditch, about 3.6 metres across and nearly a metre deep. The whole thing presents a well-formed, deliberate piece of earthwork construction, yet it yields almost nothing by way of explanation.

Enclosures of this kind are found across Ireland and can belong to a wide range of periods, from the early medieval centuries through to the post-Norman landscape of the later medieval era. The name Danescastle itself hints at a locality with a layered past. What makes this particular example quietly frustrating is that archaeological testing carried out in 2004, covering a substantial area to the north-west of the enclosure, produced no related material at all. The excavation, led by Bates and Hurley, examined a zone roughly 120 metres by 50 metres and found nothing that would tie the earthwork to a specific date, function, or phase of activity. The bank's south-western perimeter has also been cut into by a road bank running roughly north-west to south-east, suggesting the enclosure had already lost whatever significance it once held before the local road network settled into its current form.

What remains is a structure that is measurable, mappable, and entirely legible as earthwork, yet historically silent. The absence of any visible entrance adds to the oddness; most enclosures of this type retain at least a gap or a causeway across the fosse. Here, if one ever existed, it has either been obscured by vegetation and slippage or was never conventional to begin with.