No earthwork, no stone, no obvious sign that anything of historical note lies underfoot. What gives this site away is light, specifically the kind of raking summer light that, from altitude, makes crop stress visible as ghostly outlines in a growing field. It was exactly this effect, captured in an aerial photograph taken on 20 July 1996, that revealed a sub-circular enclosure roughly 55 metres in diameter, its shape betrayed by the cropmark of a fosse, a defensive or boundary ditch, cut into the soil centuries ago and long since filled in.

Cropmark archaeology works because a buried ditch, even one completely infilled with soil and debris, retains more moisture than the surrounding undisturbed ground. Crops growing above it stay greener or grow taller for longer, and from the air, especially during a dry summer, the contrast becomes legible as a pattern. The Furzehouse enclosure follows a form well known in the Irish landscape, broadly comparable to the ringed enclosures, sometimes called raths or ringforts, that were built in their thousands during the early medieval period, though a precise date for this example has not been established from the aerial evidence alone. What makes it slightly more than a single circular mark is the presence of two curving fosses extending outward from the main enclosure, one running to the northwest and one to the south. These suggest that the enclosure was not an isolated feature but part of a wider arrangement of divided land, an associated field system that once organised the ground around it.