The Cailleach is a divine hag, her name derives from the old Irish caillech, or "the veiled one”. "old woman" or "hag", She is a creator deity, weather deity, and an ancestor deity. The Cailleach Bhéirre of Ireland represents sovereignty over the land and is ancestress of many peoples.
In myth she appears to the hero as an hideous old woman seeking love; if She gets it, She becomes a beautiful young woman. In legends dating from Christian times, She is sometimes said to be a nun, perhaps linked to the meaning of Her name.
The old Irish name for the Loughcrew Mountains near Oldcastle in Co. Meath is Sliabh na Cailleach, the Mountains of the Hag. The mountain tops are crowned with the remains of a large complex of chambered cairns.
Cailleach Bhéartha came from the north to perform a magical feat by which she was to obtain great power, if she succeeded.
She took an apron full of stones, and dropped a carn on Carnbane; from this she jumped to the summit of Slieve Na Cally, and dropped a second carn there: from this hill she made a second jump, and dropped a carn on another hill, about a mile distant. If she could make another leap, and drop the fourth carn, it appears that the magical feat would be accomplished; but in giving the jump, she slipped and fell breaking her neck and here she was buried.