Dare I say that after a weekend in the Dales, Mrs. C and myself swung by Lancaster thinking that, as a historical and reportedly thriving town, there would a welcoming centre. FAIL! Apart from a couple of select boutiques I have seldom been in a more run down place.
As for "worst towns", St. Helens and Wigan are pretty up there. Wigan town centre has had a lot of cash spunked on it but still don't quite make "it". Nice ideas badly executed. There's also the southern Wiganers, i.e. Ince, Scholes, Platt Bridge etc. to contend with. All areas to avoid at all costs.
St. Helens is just a bad idea gone wrong. I'd like to say something positive about it but I can't.
It is worth nothing however that a slum never built itself. People turn a perfectly adequate place into a shitehole.