Hi Dave, If you find yourself in the North West of England, we have a thriving folk club (in it's 40th yr) in Southport.Bothy Folk Club
By the way I looked at www.visitbritain.com . What a wast of time very general & non specific. Whilst a search for folk clubs did have a couple of references to festivals it also got Newcastle nightlife, gay Manchester, Rock Sailing & Camel Ski Club!
Cheers
Les