The Inn (Latin: Aenus; Romansh: En) is a river in Switzerland, Austria and Germany. It is a right tributary of the Danube and is 517 kilometres (321 mi) long. The highest point of its drainage basin is the summit of Piz Bernina, at 4,049 metres (13,284 ft). The Inn is the only river originating in Switzerland that ends in the Black Sea (via the Danube).