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
Geology of the Alps and high peaks in the Pennine Alps and Hohe Tauern . The formation of the Mediterranean Sea is a more recent development and does not mark the northern extent of terranes originating within the African plate. The Alps form a northward convex arc around their southeastern foreland basin, the Po river basin (to be precise the south is in fact their hinterland). Quaternary and Neogene sediments in this basin lie discordant over the southernmost thrust units. In the northeast, southward dipping and internally thrusted Cenozoic foreland deposits (flysch and molasse) are found. This Bavarian and Swiss foreland basin is called