Aar (German Aare) River
The Aar rises in the great Aar Glaciers of the Bernese Alps, in the canton of Bern and west of the Grimsel Pass. It runs east to the Grimsel Hospice, below the Finsteraarhorn, and then northwest through the Haslital, forming on the way the magnificent Handegg Waterfall, 46 m (151 ft), past Guttannen. Between Innertkirchen and Meiringen, the river carves through a limestone ridge in the Aar Gorge or Aareschlucht.
A little past Meiringen, near Brienz, the river expands into Lake Brienz. Near the west end of the lake it receives its first important tributary, the Lütschine. It then runs across the swampy plain of the Bödeli between Interlaken and Unterseen before flowing into Lake Thun.
Near the west end of Lake Thun, the river receives the waters of the Kander, which has just been joined by the Simme. On flowing out of the lake it passes through Thun, and then flows through the city of Bern, passing beneath eighteen bridges and around the steeply-flanked peninsula on which the Old City is located. The river soon changes its northwesterly flow for a due westerly direction, but after receiving the Saane or Sarine it turns north until it nears Aarberg. There, in one of the major Swiss engineering feats of the 19th century, the Jura water correction, the river, which had previously rendered the countryside north of Bern a swampland through frequent flooding, was diverted by the Hagneck Canal into Lake of Bienne. From the upper end of the lake the river issues through the Nidau-Büren channel and then runs east to Büren. The lake absorbs huge amounts of eroded gravel and snowmelt that the river brings from the Alps, and the former swamps have become fruitful plains: they are known as the “vegetable garden of Switzerland”.
From here the Aar flows northeast for a long distance, past the ambassador town Solothurn (below which the Grosse Emme flows in on the right), Aarburg (where it is joined by the Wigger), Olten, Aarau, near which is the junction with the Suhre, and Wildegg, where the Hallwiler Aa falls in on the right. A short distance further, below Brugg it receives first the Reuss, and shortly afterwards the Limmat. It now turns due north, and soon becomes itself a tributary of the Rhine, which it surpasses in volume when the two rivers unite at Koblenz (Switzerland), opposite Waldshut, Germany. The Rhine, in turn, empties into the North Sea after crossing into the Netherlands.