It looks, at a glance, like an ordinary patch of land that happens to have a few mature trees growing around its edges. It is not ordinary. The island is a crannog, an artificial island constructed by hand from a pile of stones, and it is one of six such structures clustered in the same stretch of this midland lake.

Crannogs were built throughout Ireland and Scotland from the Bronze Age well into the early medieval period, typically serving as defensible lake dwellings for people of some status. The effort required to pile enough stone and timber into open water to create a stable, habitable platform was considerable, and the north-eastern end of Lough Rea appears to have supported an unusual concentration of them. This particular example measures roughly 17.5 metres from north-east to south-west and about 8.6 metres across at its widest, giving it a modest footprint not much larger than a generous suburban garden. Its grass-covered interior and the trees at its margins give it a settled, almost pastoral appearance that belies its constructed origins. Aerial imagery has also revealed a wide natural causeway, up to 43 metres across, extending from the shoreline to the north-west toward the island, which may have made access more manageable at certain water levels or seasons.