Many countries have regional variations in culture and identity. Their differences though are not so much in contrast that when they get together and show there pride at being united that their flag is one of the few things in common that they share.
Switzerland. The one thing in common the people of this country share are their great cheeses. And language is one of the great dividers in the country. Not all Swiss are German speakers, yodel and play alpine horns.
While German is by far the largest language group in the country, French, Italian, and a latin dialect called Romansh which is similar to Italian are all official languages in the country. Not only are there the differences in language but the culture within those regions.
The Röstigraben which translates as the Rösti (a Swiss type of hash brown) ditch, is the line between the German speaking Swiss and the French speaking Swiss. On either side of the line marks some large differences, but these are culture differences, because deep down no matter what the language they are all proud to be Swiss.
Equally the German speaking Swiss could call the line the Fondugraben, or in French le Rideau de Fondu, for the well known Swiss French dish of melted cheese which they dip bread into called Fondu
For many people the only thing that they will notice is the change of language as they go on a train between Geneva and Zurich. You will start your journey listening to French and end with German the spoken language as you enter the Roschtigraben.
But the differences are much more than language, and worth the discovery. The contrast in food culture and gastronomy is just as marked as the change of language. While in the Italian part polenta and pasta might be common fare, fondue and quiche in the French part, the distinction is the German part is the Röschti and Muesli, that are common there.