Where can I find some clips of obscure, hard to understand English accents?

I've heard English people speaking English, but with a regional accent so pronounced that it was virtually unintelligible. I don't necessarily mean "Cockney." In one video clip I saw, it looked like it was shot out in the country somewhere. I've heard places like Lancashire and Cornwall have pretty difficult accents. I would love to find some more video clips like that, preferably with subtitles.