“An old story about a witch living near the Ogmore River, in Glamorgan, describes a man listening to the muttering of a woman, and instantly giving her chase, with the result that in the “twinkling of an eye” he found himself on the top of the Garth Mountain, near Whitchurch.”
from chapter 16 of Marie Trevelyan’s “Folk-lore and folk-stories of Wales”, published in 1909. Online at V-Wales:
vwales.co.uk/Folklore/trevelyan/welshfolklore/chapt16.htm