The Inn is a river in Switzerland, Austria and Germany. The 518 km (322 mi) long river is a right tributary of the Danube, being the third largest tributary of the Danube by discharge. The highest point of its drainage basin is the summit of Piz Bernina at 4,049 m (13,284 ft). The Engadine, the valley of the En, is the only Swiss valley whose waters end up in the Black Sea.

Piz Bernina is the highest mountain in the Eastern Alps, the highest point of the Bernina Range, and the highest peak in the Rhaetian Alps. It rises 4,048 m (13,281 ft) and is located south of Pontresina and near the major Alpine resort of St. Moritz, in the Engadin valley. It is also the most easterly mountain higher than 4,000 m (13,000 ft) in the Alps, the highest point of the Swiss canton of Graubünden, and the fifth-most prominent peak in the Alps. Although the summit lies within Switzerland, the massif is on the border with Italy. The "shoulder" known as La Spedla is the highest point in the Italian Lombardy region.