Röstigraben (German pronunciation:[ˈrøːstiˌɡraːbən]; lit.'Rösti ditch' or 'Rösti trench', also transcribed Röschtigraben to reflect the Swiss German pronunciation [ˈrøːʃtiˌɡrabə]) is a term used to refer to the cultural boundary between German-speaking Switzerland and Romandy, the French-speaking parts. There is also the term Polentagraben, referring to the boundary between German-speaking cantons and the Italian-speakingcanton of Ticino.
The concept was first proposed by Richard Weiss in 1947, and it reflects the cultural situation in Switzerland as established by ethnographic field work during the early 20th century.Some historians and ethnographers argued that this cultural boundary is of greater importance historically than the French-German language boundary (the Röstigraben), even though it is widely admitted that the "line" doesn't form a sharp division but especially in its northern part "fans out" into a gradient.
The Sarine (French:[saʁin]; Arpitan: Sarena[ʃaʁˈnɑ]) or Saane (German:[ˈzaːnə]) is a major river of Switzerland. It is 128 km (80 mi) long and has a drainage area of 1,892 km (731 sq mi).It is a tributary of the Aare.
The Sarine rises in the Bernese Alps, near Sanetschhorn, in the Canton of Valais. It forms the Lac de Sénin (French; German: Sanetschsee) reservoir at 2034 m, and then enters the Canton of Bern, traversing the Sanetsch falls between 1900 and 1400 m. It then forms the westernmost valley of the Bernese Oberland, flowing past Gsteig, Gstaad and Saanen in the Obersimmental-Saanen district. Downstream of Saanen, at 982 m, it enters the Canton of Vaud, passing Rougemont, Château-d'Œx and Rossinière, forming the Lac du Vernex at 859 m. At 833, it traverses the Creux de l'Enfer and enters the Canton of Fribourg, forming Lac de Montbovon at 777 m.From this point, it more or less follows the linguistic boundary between French- and German-speaking Switzerland across the bilingual canton of Fribourg (and is often identified as the geographic representation of the Röstigraben division of Switzerland). Passing Villars-sous-Mont, Enney, Gruyères and Broc, it reaches Lac de la Gruyère at 677 m. It then continues in serpentines towards Fribourg itself; the historical city was built in 1157 on a peninsula of the Sarine, protected on three sides by steep cliffs. Downstream of Fribourg, it widens into the Schiffenensee reservoir at 532 m (built 1963), and is then taken to Laupen in a channel, where it is joined by the Sense. Flowing north for another 6 km, it finally joins the Aar just downstream of Wohlensee, at 461 m, some 15 km (9.3 mi) west of Bern.
