The Bernina Pass, at 2,328 metres, crosses the high Alps between the Engadine and the Valposchiavo in south-eastern Switzerland, and it is a place of water and ice. On the broad, rocky summit lie two lakes, Lago Bianco and Lago Nero, separated by a low ridge that is also a great continental watershed: water from one side flows to the Inn and the Danube and eventually to the Black Sea, while water from the other flows to the Adda, the Po and the Adriatic.
To the west, the Bernina massif rises in a wall of glaciers and snowy peaks, with Piz Bernina, the highest summit in the eastern Alps, and the beautiful ridges of Piz Palü. The Morteratsch glacier flows down from them into the valley, though it has retreated dramatically in recent decades, and signs along the trail mark where the ice once stood. A cable car from the pass road climbs to Diavolezza, with a stunning view over the glaciers.
The pass is also famous for its railway. The Bernina Express crosses the pass on a narrow-gauge line that climbs without rack assistance, one of the steepest adhesion railways in the world, and it is part of a UNESCO World Heritage Site, along with the Albula line. Its red trains wind past the lakes and down to Alp Grüm and Poschiavo, and the circular viaduct at Brusio, further south, is one of the most photographed railway structures in the Alps.
The riding is magnificent. The road from Pontresina climbs through larch forests and open moors to the summit, with long curves and wide views, and the descent to Poschiavo on the Italian-speaking side drops in a series of hairpins into a deep valley, with a change of climate and culture: chestnut trees, Italian food and a warmer feel. The pass is usually open year-round, but snow can close it briefly in winter. Watch for cyclists, tourists and trains.
Fuel is available in Pontresina and Poschiavo, and Livigno, just across the border in Italy, is a duty-free zone where fuel is cheap, so many riders detour there to fill up. Tirano, at the bottom of the valley, is the nearest large town. Stop at the summit, walk to the edge of Lago Bianco and watch the red train pass against the white glaciers.