Aar (river)

Aare
The Aare at Bern
Drainage basin of the Aare
Country	Switzerland
Cantons	Bern, Solothurn, Aargau
Settlements	Meiringen (BE), Interlaken (BE), Thun (BE), Münsingen, Muri bei Bern, Bern, Bremgarten bei Bern, Aarberg (BE), Büren a.A. (BE), Solothurn (SO), Aarwangen (BE), Aarburg (BE), Olten (SO), Niedergösgen (SO), Schönenwerd (SO), Aarau (AG), Wildegg (AG), Brugg (AG), Windisch (AG), Döttingen (AG), Klingnau (AG)
Basin features
Main source	Unteraar Glacier, Bernese Highlands 1,940 m (6,360 ft) 46°33′48″N 8°25′57″E / 46.56341°N 8.43259°E / 46.56341; 8.43259
River mouth	Rhine below Koblenz, Aargau 311 m (1,020 ft)
Progression	Rhine–North Sea
Basin size	17,779 km2 (6,865 sq mi)
Tributaries	Left: Lütschine (Lake Brienz), Kander (Lake Thun), Gürbe, Saane/La Sarine, Zihl/La Thielle (Lakes of Neuchatel and Bienne), La Suze (Lake of Bienne), Dünnern Right: Gadmerwasser, Zulg, Emme, Murg, Wigger, Suhre, Aabach, Reuss, Limmat, Surb
Waterbodies	Oberaarsee, Grimselsee, Räterichsbodensee, Lake Brienz, Lake Thun, Wohlensee, Lake Biel, Stausee Niederried, Klingnauer Stausee
Physical characteristics
Length	288.2 kilometres (179.1 mi)
Discharge	Location: Untersiggenthal Minimum rate: 351 m3/s (12,400 cu ft/s) (MNQ 1935-2013), 138 m3/s (4,900 cu ft/s) (NNQ, 1963) Average rate: 559 m3/s (19,700 cu ft/s) (MQ 1935-2013) Maximum rate: 735 m3/s (26,000 cu ft/s) (MHQ 1935-2013), 2,656 m3/s (93,800 cu ft/s) (HHQ, 2007)

The Aare (German pronunciation: [ˈaːrə]) or Aar is a tributary of the High Rhine and the longest river that both rises and ends entirely within Switzerland.

Its total length from its source to its junction with the Rhine comprises about 295 kilometres (183 mi), during which distance it descends 1,565 m (5,135 ft), draining an area of 17,779 km² (6,865 sq mi), almost entirely within Switzerland, and accounting for close to half the area of the country, including all of Central Switzerland.

There are more than 40 hydroelectric plants along the course of the Aare River.

The river's name dates to at least the La Tène period, and it is attested as Nantaror "Aare valley" in the Berne zinc tablet.

The name was Latinized as Arula/Arola/Araris.

The Aare rises in the great Aargletschers (Aare Glaciers) of the Bernese Alps, in the canton of Bern and west of the Grimsel Pass. The Finsteraargletscher and Lauteraargletscher come together to form the Unteraargletscher (Lower Aare-Glacier), which is the main source of water for the Grimselsee. The Oberaargletscher (Upper Aare-Glacier) feeds the Oberaarsee, which also flows into the Grimselsee. The Aare river leaves the Grimselsee just to the east to the Grimsel Hospice, below the Grimsel Pass, and then flows northwest through the Haslital, forming on the way the magnificent Handegg Waterfall, 46 m (151 ft), past Guttannen.