These are the Balie Islands, a pair of crannóga, artificial or partly artificial islands built out into open water during early medieval times or earlier as defensible habitation sites. What makes them quietly remarkable is not what survives above ground, which is very little, but the layered process by which they vanished, were named, and were partially recovered through aerial photography.

Both islands appear on the 1840 first-edition Ordnance Survey six-inch map, at which point Lough Gur was still substantially intact. Mid-nineteenth-century drainage works reduced the water level and shrank the lake considerably, and by the time the 1897 twenty-five-inch edition was produced, neither island was shown; the area is depicted simply as wet marshland prone to flooding. Writing in 1896, Dowd described two slight elevations perceptible above the drained ground, noting they appeared to be crannóga constructed when the surrounding area was a flooded morass. By 1944, O'Kelly reported that all efforts to trace them had failed. It was aerial survey that eventually resolved the question; orthoimages taken between 2005 and 2013 show one crannóg as a circular stand of trees roughly 27 metres in diameter on marshy ground. The name Balie Islands is itself historically layered. Cleary, writing in 2018, linked it to John Bayley, whose family occupied nearby Bouchier's Castle as agents of the Fane family from the late seventeenth century. There may also be a connection to Caheer Baelee, meaning Bayley's Chair, a site on Knockderc Hill about 2.5 kilometres to the south. The two crannóga sit within one of the most archaeologically saturated landscapes in Ireland, with Early Medieval stone forts at Carraig Aille some 320 metres to the east, a bullaun stone, a large boulder with a carved hollow basin often associated with early Christian sites, less than 300 metres to the north, and the possible site of a church called Killalough roughly 375 metres to the south-west.

The crannóga lie in the drained eastern section of Lough Gur, west of the shallow water that remains, and accessing the immediate area means navigating ground that is still described in survey records as marshy and liable to flooding. The northern crannóg sits approximately 50 metres north-north-east of its southern companion. At ground level there is little to distinguish either from the surrounding wet grassland, but looking at current satellite imagery before a visit gives a clearer sense of their outlines, particularly the circular tree cover that marks the northern site. The wider Lough Gur landscape rewards careful attention to the map; Bouchier's Castle and the Carraig Aille forts are both within easy walking distance, and the density of monuments in this area means that almost any direction of travel brings something else into view.