That causeway, and the island it leads to, are the visible remains of a crannóg, a type of artificial or partly artificial island dwelling used in Ireland from the Bronze Age through to the early modern period. What makes this particular example quietly interesting is that it is not purely man-made: it began as a natural islet of limestone bedrock and was then deliberately enhanced, with cairns of stones arranged across the surface and large boulders laid against the south-eastern side of the outcrop. The bedrock itself juts noticeably above the waterline to the north-west, giving the site a layered quality, part geology, part human intervention.

Aidan O'Sullivan, who surveyed and described the site, catalogued it as Kiltoom 10, placing it within a broader study of crannóg usage across Irish lakes. The ancient shoreline, he noted, lies about fifty metres to the north-east, meaning the water level has changed over time and what was once a more clearly isolated island is today practically at the water's edge, with depths of only around one metre off its western side. The steep slope overlooking the site from the north-east would have made the crannóg naturally defensible and visually commanding, with open views stretching north-west, west, and south-west across the water. The causeway, while ancient in origin, appears to have been widened or reinforced at some point by modern land clearance activity, blurring the line between its original form and more recent practical use.

Today the island hosts three duck hides positioned to the north, north-east, and south, so the site has slipped quietly into use as a wildfowling spot, its prehistoric origins unremarked upon by anyone settling in for a morning's wait. The limestone outcrop and the scatter of boulders across its surface are still plainly visible, and the causeway remains a functional, if unassuming, crossing point to what was once, in all likelihood, someone's carefully chosen home.