The Albula Railway is a single track metre gauge railway line forming part of the so-called core network of the Rhaetian Railway, in the canton of Graubünden, Switzerland. It links Thusis on the Hinterrhein at 697 m and Filisur at 1,080 m with the spa resort of St. Moritz in Engadine at 1,774 m.
Construction of the Albula Railway was begun in September 1898, the opening took place on 1 July 1903, and the extension to St. Moritz commenced operations on 10 July 1904. With its 55 bridges and 39 tunnels, the 61.67-kilometre long line is one of the most spectacular narrow gauge railways in the world.
Wikipedia https://en.wikipedia.org/wiki/Albula_Railway
Coordinates 46°37'53.558" N 9°44'47.216" E