Krakow is great, I have never been to Birmingham but I hear good stories from it, from an architectural point of view.
I had a great time, the only dark spot being Katowice...
I am not native Polish but I think it is widely known that katowice was of communist design and meant to "show off" communism.
Also built up wind from Krakow apparently cause the commies didn't like old stuff and wanted to destroy it, to build a new.
I live close enough to Bielsko-Biala, it is lovely here.
But I am afraid I do not know the cliffs and lake you are talking about.
Have you any photos to show us??