And, of course, a 'cwm' or 'tarn' is a hole in a mountain that has been scraped out by a glacier into a sort of a 'D' cup on it's side, kind o' shape.
All the little rivers that used to run down that mountain, before the big, bad, glacier came, ran down into the hole it left, after the Ice Age was over, you understand, and made this holy bejasus lake.
I wonder if these boys that invented the word could astral walk?

B.