The only exception within German-speaking Switzerland is the municipality of Samnaun where an Austro-Bavarian dialect is spoken.
German is the sole official language in 17 Swiss cantons (Aargau, Appenzell Ausserrhoden, Appenzell Innerrhoden, Basel-Stadt, Basel-Landschaft, Glarus, Lucerne, Nidwalden, Obwalden, Schaffhausen, Schwyz, Solothurn, St. Gallen, Thurgau, Uri, Zug, and Zurich).
In Germany Welsch and Welschland refer to Italy; there, the term is antiquated, rarely used, and somewhat disparaging.
After the Reformation, all cantons were either Catholic or Protestant, and the denominational influences on culture added to the differences.
Even today, where all cantons are somewhat denominationally mixed, the different historical denominations can be seen in the mountain villages, where Roman Catholic Central Switzerland abounds with chapels and statues of saints, and the farm houses in the very similar landscape of the Protestant Bernese Oberland show Bible verses carved on the housefronts, instead.