It does not announce itself with earthworks or stone. Instead, it registers only as a series of narrow, weakly magnetic curving responses, the kind of subtle underground signature that geophysical survey equipment can detect but that the naked eye simply cannot resolve. That near-invisibility is part of what makes it interesting.

The enclosure was first identified through geophysical analysis undertaken by Ó Lionáin and Davis in 2014, with further characterisation carried out by Target in 2018. The fact that it required specialist survey work to locate at all suggests it has been largely undisturbed since whatever prehistoric or early historic community used it, though its precise date remains unknown. What the surveys also revealed is that this is not an isolated feature. Within the enclosure, sitting at the hilltop's centre, is a continuous ring-ditch, a roughly circular earthwork trench that in Irish archaeology is often associated with burial or ritual use. Just off-centre to the north-east of that ring-ditch sits a cairn, a mound of stones that may mark a burial, and the remains of a windmill. The whole complex appears to lie within the bounds of a possible hillfort. A second ring-ditch lies approximately 80 metres to the south-east, outside the enclosure proper. The northern arc of the large enclosure has been cut away by quarrying, which runs from the north-west to the north-east, so whatever originally existed on that side is gone.

Windmill Hill is not a managed heritage site, and there is no visitor infrastructure. The enclosure itself is invisible at ground level; nothing marks it out in the field. What a visitor can see are the landscape layers that the geophysical record places in context, the hilltop position, the remnant windmill structure, and the general topography that made this a significant place across several different periods. The enclosure is most clearly resolved in imagery taken from the west, south, and east, fading towards the north-east and north-west, which is worth bearing in mind if you are reviewing aerial or geophysical data rather than walking the ground.