It is recorded as a crannog, a type of artificial or partly artificial island dwelling built on lakes and marshes, used in Ireland from the Bronze Age through to the early modern period as defensible homesteads. At roughly 60 metres along its longest axis and 30 metres across, this was not a modest structure in its time. Today, you would have little chance of finding it.

Ordnance Survey maps from 1838 and again from 1922 both clearly mark the island sitting in the narrow south-western arm of Ballymore Lough. That it appears on both surveys suggests the feature was still a legible presence in the landscape well into the twentieth century. Since then, that end of the lake has dried out considerably. What was once open water is now a stretch of boggy ground thick with bog myrtle, sedges, coarse grasses, scrub willows, and gorse. The drying out of this shallow lough margin has, paradoxically, swallowed the crannog rather than exposed it. The vegetation has colonised and obscured whatever earthwork or stony mass once projected above the waterline, and the outline of the island can no longer be made out at ground level.