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capital, Graubunden (Grisons) canton, eastern Switzerland. It lies on the Plessur River in the Rhine Valley. The meeting point of roads from Italy over several Alpine passes, it was important in Roman times as Curia Raetorum, the centre of the Roman province of Raetia. First mentioned in 452 as the seat of a bishopric, it was ruled in the Middle Ages by its bishops, who became princes of the Holy Roman Empire in 1170. Chur was the centre of the Gotteshausbund (League of the House of God) against the power of the prince bishops and the Habsburgs in 1367, and it became the capital of the new canton of Graubunden in 1803. Notable landmarks include the Catholic Cathedral (1175-1282), the Episcopal (Bishop's) Palace (rebuilt 1728-37), the Protestant Church of St. Martin (8th century, rebuilt 1476-91), the Raetian Museum, and art and natural history museums.
largest and most easterly canton of Switzerland; it has an area of 2,743 square miles (7,105 square km), of which two-thirds is classed as productive (forests covering one-fifth of the total). The entire canton is mountainous, containing peaks and glaciers of the Todi (11,857 feet [3,614 metres]), Bernina (13,284 feet), Adula, Albula, Silvretta, and Rhatikon ranges in the Central Alps. These ranges are penetrated by a system of level valleys, of which the inner ones are the highest in central Europe. The principal valleys, running southwest to northeast, are those of the Upper Rhine