It was built, by hand, and on it someone raised a cashel, a type of ringfort defined by a drystone enclosure wall rather than an earthen bank. The island measures roughly twenty metres across its longest axis, north to south, and just under eighteen metres east to west, making it a compact and deliberate construction rather than any accident of glacial geography.

A cashel of this kind would typically have served as a defended farmstead or the seat of a minor local lord during the early medieval period, though no specific date has been attached to this particular site. What survives is fragmentary. A section of drystone wall, standing no higher than a metre at its best, runs from the eastern to the south-eastern arc of the enclosure; everywhere else it has collapsed entirely. The interior is partly overgrown, and there is a noticeable unevenness to the ground: the northern half of the island sits considerably higher than the southern, a detail that hints at underlying structural remains beneath the vegetation and rubble, though their nature is unrecorded. The site was noted by Tim Robinson, the cartographer and writer whose meticulous mapping of Connemara and the Aran Islands brought many such overlooked features to wider attention, and his 1985 reference remains the primary source for what little is documented here.

The lake shore provides the closest approach, though the island's position in the water means any closer inspection would require more than a casual walk. The overgrowth and collapsed masonry make the interior difficult to read, but the surviving eastern wall section and the pronounced change in ground level across the interior are the details most worth looking for.