Piz Bernina (Romansh, , ) 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 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 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. Piz Bernina is entirely surrounded by glaciers, of which the largest is the Morteratsch Glacier. The mountain was named after the Bernina Pass in 1850 by Johann Coaz, who also made the first ascent. The prefix Piz comes from the Romansch language in Graubünden; any mountain with that name can be readily identified as being located in southeastern Switzerland. Geography Piz Bernina is one of the few isolated Alpine four-thousanders and the most topographically isolated mountain of Switzerland. It is the culminating point of a group of summits slightly lower than mostly lying on the main watershed between Switzerland and Italy (such as Piz Scerscen, Piz Zupò, and Piz Palü). The only other summit higher than is La Spedla (the Shoulder), a minor prominence south of the mountain, which is also the highest point on the Italian side of the massif. The summit itself is located on a perpendicular chain (orientated north–south) starting at La Spedla on the border and finishing at Piz Chalchagn, composed also of Piz Morteratsch and Piz Boval. Piz Bernina separates two glacial valleys, the Tschierva Glacier on the west and the Morteratsch Glacier on the east. The waters flowing on both side of the mountain end up in the Inn River running northeast through Engadin. South of Piz Bernina the watershed separates the drainage basins of the Danube (Black Sea) and the Po River (Adriatic Sea). The summit of Piz Bernina is the culminating point of the Danube drainage basin. Politically, it is split between the municipalities of Samedan and Pontresina. Geology The rocks composing Piz Bernina are mostly diorites and gabbros. The massif in general is also composed of granites, notable on Piz Corvatsch and Piz Palü. Most of the range belongs to the Austroalpine nappes,