The hook
A day-long train billed as the slowest express in the world, crawling across a viaduct that curves into a cliff, over passes, and down to Italian-speaking valleys, on a line hand-built through mountains a century ago.
01Why it's worth it
The Rhaetian Railway through Graubünden is a feat of early-twentieth-century engineering: a narrow-gauge line that climbs and descends serious Alpine terrain with no cog assistance, using spiral tunnels and soaring stone viaducts to gain height. The signature is the Landwasser Viaduct, a curving arched bridge that runs straight into the mouth of a tunnel in a rock face. The Glacier Express rides much of this over a leisurely full day between Zermatt and St Moritz; the connecting Bernina line climbs higher still, over a glacier-flanked pass and down to palm-lined Italian-speaking Poschiavo, one of the steepest adhesion railways anywhere. It is a place you experience through a window, and the older open routes and slower regional trains often beat the branded express on both price and views.
02How to experience it
You don't need the pricey panoramic Glacier Express to see this. Regular Rhaetian Railway regional trains cover the same track for far less, and the Bernina line from Chur or St Moritz down to Tirano is the most dramatic stretch on its own. Sit on the correct side (staff or a quick search will tell you), and consider hopping off to photograph the Landwasser Viaduct from the trail below.