None know for certain who built the dolmens on this island, but many say that it was Diarmad who built them as he fled the rage of Fionn.
Now Fionn had lived a long life and had many great endeavors to his name by the time he met the beautiful young Grainne, daughter of High King Cormac the Bear. His other wives had long since died and so Fionn was convinced to marry Grainne, though Grainne was less than eager about marrying such an old man. By this time Fionn was settled into a great hillfort on the Hill of Allen, but despite his old age he would often range out by day or by night with his two hounds at his hunting for days and weeks at a time. All a man such as Fionn could offer a fresh young bride was a gypsy life in the wilds, or a life of loneliness and isolation in a windy hilltop fortress.
So, dejected but headstrong, Grainne convinced one of Fionn’s most loyal warriors to neglect his oaths of service to his Warband, and to flee with her into the wilds. He went reluctantly at first with the intention of protecting her, convinced that she would change her mind after one night in the wet Irish weather. But she persisted, and as time passed they grew closer in their exile until at the last they loved each other dearly. But it was a life of great hardship they endured, for they had chosen the path of exile from their tribes, and were hunted day and night by Fionn Demne Mac Cumhal, Rigfènnid of Cormac Mac Art’s Fianna.
For protection by night from storms and ambush, Diarmad used his great strength to pile massive stones into defensible shelters, often covering them in earth to conceal them completely. But it was in vain, for there was never born a man or a beast that could outrun the pursuit of Fionn. Eventually the two fugitives fell into his power, but were saved by the diplomatic intervention of Diarmad’s foster father, Oenghus. Fionn bade his time, and when at last the dispute had long been forgotten by others he took his revenge on Diarmad the betrayer of oaths.
Now Diarmad is gone, and Fionn is gone, and all of those heroes who once strode the earth like Giants are gone too. The only thing which survives from that age of wonder and high adventure are the hills upon which they built their forts, and the dolmens which once protected two fugitive lovers from harm.