The Bernina Express crosses the Swiss Alps from north to south, from Switzerland’s St Moritz to Tirano in Italy – the facts do little to convey the majesty of the journey. This is one of the world’s great train journeys, a series of spiralling viaducts and breathtaking hairpin bends, imposing glaciers and the Eastern Alps’ highest summits. An engineering marvel, the line rises to a mountain pass of well over 2,000 metres, sometimes at a gradient of 7 percent, with mighty tunnels forged deep in the mountains. But it’s the jaw-dropping views that stay with you: cutting past Europe’s most beautiful mountains, through the shimmering eternal snow, then down past emerald lakes and alpine meadows. Only the third railway in the world to be placed on UNESCO’s world heritage list, riding the rails here you’ll wonder why it wasn’t the first.