Switzerland in the Roman era after which the area began to be occupied by Germanic peoples. The Swiss plateau, within the natural borders of the Alps to the South and East, Lake Geneva and the Rhône to the west and the Rhine to the north, was recognized as a contiguous territory by Julius Caesar. This area had been dominated by the La Tène culture since the 5th century BC, settled by a mostly Celtic population (Gauls), of which the Helvetii were the most numerous, but which also included the Rauraci in north-west Switzerland centered on Basel, and the Allobroges around Geneva. South of the Swiss
Swiss Alps on the shores of Lake Geneva to Rorschach on the shores of Lake Constance, passing close to the cities of Thun and Lucerne. The not well defined regions in Switzerland that lie on the margin of the Alps, especially those on the north side, are called the "Swiss Prealps" ("Préalpes" in French, "Voralpen" in German, "Prealpi" in Italian). The Swiss Prealps are mainly made of limestone and they generally do not exceed . The Alpine cantons (from highest to lowest) are Valais, Bern, Graubünden, Uri, Glarus, Ticino, St. Gallen, Vaud, Obwalden, Nidwalden, Schwyz, Appenzell Innerrhoden, Appenzell Ausserrhoden, Fribourg, Lucerne and