It is a crannog, an artificial island built from timber, stone, and organic material, constructed in the lake by people who wanted to live on water rather than beside it. Such structures were common across Ireland and Scotland from the early medieval period onward, offering a degree of security that dry land could not always provide. What makes this particular example quietly arresting is how much of its original fabric survived long enough to be recorded.

When the geologist George Henry Kinahan examined the island in 1863, he found its surface covered in flat stones that continued below the waterline on its eastern and western sides, with short spurs projecting off to the north and southwest. Beneath the water at the northeastern and eastern edges, parallel logs of round ash timber were still visible, alongside oak piles at the northwest and northeast. Kinahan dug into the eastern side and recovered animal bones, broken and whole hazel nuts, two hones used for sharpening blades, and the remains of a wicker wall running east to west. The hazel nuts in particular are a common find on crannog sites, pointing to the kind of everyday diet and seasonal food storage that sustained people living on these islands. A dive carried out in the late 1990s added further detail, with traces of posts identified along the western to northwestern edge of the structure.