AAR or AARE, ar (“river”), the name of several German streams: chiefly, a Swiss river tributary to the Rhine, about 175 miles long, the largest in Switzerland save that and the Rhone. Formed by torrents from the vast and famous Oberaar and Unteraar glaciers of the Bernese Alps in E. Bern, it flows northwest through the valley of Hasli over the Handeck Falls, 200 feet high, expands into Lake Brienz, and past Interlaken into Lake Thun, becomes navigable, passes Bern, turns north and then northeast along the southern slopes of the Jura, past Solothurn and Aarau, and joining the Limmat, shortly after breaks through the ridge and empties into the Rhine at Waldshut. Chief affluents, the Saane, Zihl, and Emme, the Reuss feeding it from the lake of Lucerne and Zuger See, the Limmat from the lake of Zurich and the Lütschine from the two splendid Grindelwald glaciers. The chief cities on its banks are Bern, Solothurn, Aarau and Interlaken.