The Bernina railway is a single-track 1,000 mm (3 ft 3 3⁄8 in) metre gauge railway line forming part of the Rhaetian Railway (RhB). It links the spa resort of St. Moritz, in the Canton of Graubünden, Switzerland, with the town of Tirano, in the Province of Sondrio, Italy, via the Bernina Pass. Reaching a height of 2,253 metres (7,392 ft) above sea level, it is the highest railway crossing in Europe and the third highest railway in Switzerland. It also ranks as the highest adhesion railway of the continent, and – with inclines of up to 7% – as one of the steepest adhesion railways in the world.