Old Ordnance Survey maps from 1839 and again from the 1898 revision mark a small island near the lough's south-eastern end, but nothing about that notation suggests anything more than a modest patch of ground above the waterline. It took an unusually prolonged dry spell in the summer of 2010 to reveal what had been sitting just beneath the surface all along: the remains of a crannog, an artificial or partly artificial island of the kind built and inhabited in Ireland from the Bronze Age through to the early modern period, constructed here from a roughly circular arrangement of stone walling roughly fourteen metres north to south and eleven metres east to west.

When the water level dropped far enough to expose the structure, it became clear that the crannog's entrance had faced east, and that wave action over the centuries had sluiced out most of whatever material once filled the interior. The stone wall defining its perimeter, however, remained legible. Later aerial imagery has suggested the possibility of a causeway extending to the south-east from the entrance point, which would have provided a connection to the lakeshore, a common feature of crannog design that allowed controlled access while keeping the dwelling effectively island-bound. The site was reported in the Irish Times in June 2010 by journalist Lorna Siggins, who documented its emergence from the receding water.

Because the crannog sits at the south-eastern end of the lough and is only fully visible when water levels are exceptionally low, there is no reliable time to guarantee a clear view of it. The summer of 2010 was a particular accident of drought rather than a seasonal pattern. What remains visible at ordinary water levels is, by all accounts, very little.