What does it all mean?

It used to be thought that Pen yr Ole Wen translated as ‘Head of the White Light’, although nobody was entirely sure why the mountain was so called. Then in 2004 a chap called Bill Hughes pointed out that there was a problem with this. You see, it was previously thought that ‘Ole’ came from the word ‘Golau’ meaning light, and the ‘Wen’ was a mutation of ‘Gwen’ meaning white. “Ahh,” said Bill, “but Golau is a masculine noun, and Gwen is the female form of the adjective, so the two don’t match”. Subsequently, Professor Hywel Wyn Owen at the Place-Name Research Centre at Bangor University did some digging and determined that ‘Ole’ actually derives from ‘Goleddf’ meaning slope or hillside, making the new and current translation of Pen yr Ole Wen ‘Head of the White Slope’.