The ancient pagan shrine of Tigh nam Bodach is located in Glen Cailliche (the Crooked Glen of the Stones), north of Loch Lyon. The shrine is made up of a modest stone structure that houses a family of three bell shaped water stones from the river bed of the Lyon. The largest represents the Cailleach (old woman), accompanied by the Bodach (old man) and their daughter, Nighean. In what is believed to be the oldest uninterrupted pre-Christian ritual in Britain, the water-worn figures from the River Lyon are taken out of their house every May and faced down the glen, and returned every November.

The ritual marked the two great Celtic fire festivals of Beltane(Summer)  and Samhain (Winter)and the annual migration of Highland cattle on and off the hills. Legend states that The Cailleach, in the tradition of the Celtic mother-goddesses, blessed the stock and the pasturage and ensured good weather and "strange and terrible" things could happen to those who dared disturb her wintering grounds in Glen Cailliche.

The Cailleach, or divine goddess, is a potent force in Celtic mythology, commonly associated with wild nature and landscape. A local myth says that Loch Tay was formed when she forgot to leave a flagstone lid on a magical spring well.