In a field on a gentle south-westerly-facing slope in Rannagh, County Clare, an enclosure of some kind once existed, or at least left enough of a trace to be drawn onto a map. Today, after extensive land reclamation turned the surrounding area into managed pasture, it has vanished entirely at ground level.

The site appears on the 1842 edition of the six-inch Ordnance Survey map, rendered in hachures, the small lines surveyors used to indicate an earthwork or raised feature with some relief to it. By the time the 1915 edition was produced, the same feature was shown with a solid line rather than hachures, suggesting the earthwork had by then been reduced to something closer to a flat boundary or barely perceptible outline. Between those two map editions, and almost certainly continuing long afterwards, the gradual process of agricultural improvement was doing its work. Reclamation of this kind, which typically involved draining, levelling, and turning rough ground into productive pasture, has erased a great many early enclosures across Ireland. These enclosures could have served a wide variety of purposes: some were associated with early settlement, others with livestock management, field boundaries, or the remains of a ringfort, which is a circular earthen or stone enclosure that formed the basic unit of rural settlement in early medieval Ireland.

What the enclosure at Rannagh actually was remains uncertain, and without visible remains or excavation there is little more to say with confidence. It now exists primarily as a cartographic ghost, traceable through the gap between two map editions and the note that nothing survives above ground. That gap of roughly seventy years, between one map and the next, contains the story of its disappearance.