On 16 July 1989, an aerial photograph captured the cropmark of a circular enclosure, its outline betrayed by the differential growth of crops over buried soil disturbances. The mark reveals a fosse, a defensive ditch, tracing the perimeter of what was once a defined and enclosed space, with an entrance oriented to the north-east.

Cropmark archaeology works on a simple principle: buried ditches retain moisture and nutrients differently from the surrounding subsoil, and in dry conditions that difference shows up in the colour and height of growing crops above them. The enclosure at Moorstown has never been excavated, so its date and precise function remain unconfirmed, but circular enclosures of this kind are found across Ireland and typically belong to the early medieval period, sometimes serving as ringforts or enclosing farmsteads, sometimes associated with ritual or funerary use. The north-east entrance orientation is a detail worth noting; it recurs often enough in Irish enclosures to suggest it carried some significance, though the reasons remain debated. Roughly fifty metres to the south lies a ring-ditch, a related but distinct feature, usually interpreted as the ploughed-down or eroded remnant of a burial mound. Whether the two features are contemporary or simply neighbours across a longer stretch of time, their proximity in the same field hints at a landscape that was, at some point, deliberately organised.