Shown clearly on the 1840 Ordnance Survey six-inch map under the label 'Balie Islands', they had vanished from later editions entirely, and by 1944 a researcher named O'Kelly noted plainly that 'all efforts to trace them have failed'. They are crannóga, a type of artificial or semi-artificial island dwelling built in lakes or wetlands and used across Ireland from the Bronze Age through to the early modern period, and their disappearance is largely a matter of hydrology. When Lough Gur was drained in the mid-nineteenth century, the water level dropped, the surrounding lake became wet marshland liable to flooding, and the slight elevations that had once been islands simply merged with the boggy ground around them.

The sites sit within one of the most archaeologically layered landscapes in Ireland, with Neolithic and Bronze Age activity at Lough Gur documented extensively by researchers including Cleary in 2018. Within a few hundred metres of the crannóga lie the Early Medieval Carraig Aille stone forts on a rocky ridge to the southeast, the site of a possible church known as Killalough to the southwest, a bullaun stone (a boulder with one or more cup-shaped hollows, often associated with early Christian or earlier ritual use) to the north, and Bouchier's Castle just 260 metres to the northwest. The 'Balie Islands' name, it turns out, has nothing to do with medieval Gaelic nomenclature. Cleary associated it with a Mr John Bayley, whose family occupied Bouchier's Castle as agents of the Fane family from the late seventeenth century, a connection reinforced by a site on Knockderc Hill 2.5 kilometres to the south known as Caheer Baelee, or Bayley's Chair, named for the same family.

For a visitor today, the southern crannóg is the more traceable of the two. Aerial imagery from 2005 onwards shows it as a circular stand of trees roughly 30 metres in external diameter, sitting on marshy ground north of shallow water. The ground here remains wet and difficult, so approaching on foot requires care and appropriate footwear. The northern crannóg, just 50 metres to the north-northeast, is considerably harder to locate at ground level. Both are easier to appreciate from aerial images than from the lakeshore path, and a look at Google Earth before visiting gives a useful sense of the circular wooded outline to watch for. The wider Lough Gur landscape rewards slow attention; the crannóga are easy to walk past without realising what the trees are marking.