The creation of Loch Awe and Loch Ness were mentioned in the previous post, so here’s a bit more:
The Scottish stories about the Cailleach are far more alive and more widely spread than those in Ireland. They make her a one-eyed hag, of great age, who reigned over the Four Red Divisions of the World. She let loose the rivers, and formed many lochs. Loch Awe was formed through her forgetfulness; for she drew water daily from a well on Ben Cruachan in Argyle, lifting the slab off it in the morning and re-covering it at night. But one evening she forgot to cover the well, and, furious at being forgotten, the waters rose and poured down the mountain side, roaring like a torrent. In the morning the valley was filled with water, and Loch Awe was formed. This story is told of the origin of many rivers and lakes. The River Boyne was so formed in Ireland, by the recklessness of its attendant nymph, who in defiance of all the laws of folk belief dared to walk thrice ‘withershins’ round the well. It rose furiously upon her, and drove her before it to the sea.
All she left behind her was her name, which she gave to the river. So also it is told of the Cailleach that she had another well in Inverness which had to be kept covered from sunset to sunrise. It was in charge of her maid Nessa. But one evening she went late to the well, and, when she drew near, water was pouring out of the well after her. She turned and fled, but Beira, who was watching her from the top of Ben Nevis, cried aloud,-“You will run for ever and ever, for you have neglected your duty, and will never leave the water.” The girl changed into a river, and after her the Loch and River Ness are named. Once a year, on the date of her transformation, Ness rises from her river and re-assumes her form as a girl, singing a sad sweet song in the moonlight.
Hull, Legends and Traditions of the Cailleach Bheara or Old Woman (Hag) of Beare, in Folklore, Vol. 38, No. 3 (Sep. 30, 1927), p249-250.