An early archaeological survey noted the possible presence of two crannogs; artificial island dwellings that were once common across Ireland during medieval times. These wooden structures, built on stilts or artificial mounds in lakes and marshes, served as defensive homesteads for families seeking protection from raiders and rival clans. What makes the Lough Adeery sites particularly intriguing is their elusive nature; with no visible islands present in the lake today, these crannogs appear to have become completely submerged over the centuries.

The sites at Carrickataggart represent just a fraction of Donegal's rich archaeological landscape, which spans from the Mesolithic period through to the 17th century. Crannogs were particularly popular between the early medieval period and the 1600s, when political instability made defensible homes a necessity. These lake dwellings typically featured a single roundhouse surrounded by a wooden palisade, accessible only by boat or a narrow causeway that could be easily defended or destroyed if needed.

The mystery surrounding these potential underwater crannogs highlights how much of Ireland's archaeological heritage remains hidden from view. Without proper inspection, it's impossible to confirm whether these are indeed crannogs or perhaps natural features misidentified in early reports. The information comes from the comprehensive Archaeological Survey of County Donegal, compiled in 1983 by Brian Lacey and his team, though the sites themselves remain uninvestigated. Like many archaeological features across Ireland, these possible crannogs wait patiently beneath the water's surface, keeping their secrets until technology or lowered water levels might one day reveal their true nature.