“Horned Mount”
A mountain in Britain on which two oxen lived: Nynnyaw and Peibyaw.
As one of his tasks, the warrior Culhwch had to travel to Mynydd Bannawg and capture the oxen.
Notes
The Welsh word for mountain is mynydd, which derives from mwn, and is a mountain rising considerably above the surface of the surrounding land.
Source
Culhwch and Olwen | Late 11th century