Dyffryn Llochwr
During the quest associated with Dyffryn Llwchwr, Culhwch and his companions are tasked with finding the magical cauldron of Diwrnach the Irishman. This cauldron is described as a prized and wondrous item, known as the Cauldron of Rebirth or the Cauldron of Plenty. It had the mystical ability to bring dead warriors back to life when they were placed inside it, and it was believed to be located in the valley Dyffryn Llwchwr.
The specific challenges and encounters that Culhwch and his companions face in Dyffryn Llwchwr are not detailed in the tale.
Notes
The word dyffryn is popularly derived from dwfr, which is the Welsh word for water, and hynt, which means a way, a course. That is a water-course, or a vale, through which a river takes its course. It may be a compound of dwfr-bryn, signifying a hilly place through which water flows. See also notes under Glyn Arthur.
Source
Culhwch and Olwen | Late 11th century