Montleek: Robert, is it possible that in Western Europe, the regional lects have been preserved better, while in eastern Europe are preserved worse? There was communism/socialism in Eastern Europe, therefore more tendency not to continue speaking with regional lect.
In France, the regional lects are the langues d’ oil (still spoken, believe it or not!), Occitan, Breton, Alsatian, Franconian, Arpitan, and Flemish.
With Arpitan, Alsatian, Occitan and the langues d’oil, you can definitely get to the point of having a different lect in every major city if not every town in some cases.
There are a number of languages split through these regional lects. There are probably at least 10 full languages in the langues d’oil, ~20 in Occitan and Arpitan, five in Breton and more than one in Alsatian. The Flemish spoken in France is a separate language from that spoken in Belgium, hardly intelligible to a Belgian.