Aubrey Burl, in Megalithic Brittany says: “legend has it that fairies lived in the tomb’s ruins. When their cow trampled on some crops they compensated the farmer with a magic loaf, saying it would never grow less or harden s long as he kept his promise. Forgetting his promise the farmer boasted of his prize one day and the loaf instantly became as hard as brick.”
French farmers, eh?!