Few countries lend themselves to sightseeing by train as well as Switzerland. In this country of mountains, lakes and valleys, it’s the ideal way to travel. Avoiding airport hassles, travelling there by rail adds an extra dimension to the holiday. There’s great pleasure in watching Europe’s landscapes unfold through picture windows.

The sense of Continental style begins as soon as you leave London’s St Pancras International station aboard a sleek Eurostar train. It is pleasantly relaxing to watch the Kent countryside zip by. At Brussels Midi station it’s an easy connection to a German intercity ICE train, speeding along to Cologne in comfort levels above even those of Eurostar and the TGV.

The entire journey from London, through France, Belgium and Germany, takes around six hours, leaving plenty of energy for a walk through the centre of Cologne and a visit to the spectacular cathedral there. The city has plenty of good hotels and restaurants and is ideal for an overnight stay.

On to Chur

Then from Cologne to Chur, Germany to Switzerland, via towns with evocative names – Koblenz, Mainz, Mannheim and Baden Baden and Basel – and the cities of Basel and Zurich. It’s a grand day’s travelling.

Through the domed observation car of a EuroCity train you see castles standing sentry over the wide and winding River Rhine, where laden barges travel low in the choppy green water. Neat houses clamber into tree-covered hillsides punctuated by churches with needle spires and baroque bonnets topping sturdy towers. There are tall cliffs and vineyard-terraced slopes, jagged rocks and sandy islands green with trees; red-roofed towns and farming villages, orchards and industry, the spectacular Rhine Gorge and Zurich’s vast lake.

Situated at the foot of the Calanda mountain, Chur has the best shopping between Zurich and Milan. High street and department stores are found in the modern city and small specialist shops seem made for browsing in the medieval streets and pleasing squares of the old town. They vie for your attention among historic churches and painted houses, the 15th-century Town Hall, taverns, restaurants and hotels in the romantic style.

The late Romanesque cathedral, which dates back to the 13th century and is surrounded by canon’s houses and the Episcopal Castle, appears like a mini fortified town above the old town’s streets.

Chur was under Roman rule for 400 years, when the region was known as Rhaetia, and for centuries has been a transport hub to the north of the passes over the Alps. The first train steamed towards the town in 1858. Today the Arosa Railway travels through the city’s centre before it begins its winding climb up to the famed mountain resort of Arosa. And Chur, Switzerland’s oldest city, is the starting point for the narrow-gauge Rhaetian Railway’s Bernina Express to Tirano in Italy, the picture windows of its domed observation cars cleaned to a sparkle.

The Bernina Express

Leaving Chur and its mountain behind, the Bernina Express travels by a glacially turquoise river and through a valley dotted with strange little hills – tumas – the remains of a massive, pre-historic landslide.

Cloud drifts among wooded mountain slopes and steep-roofed, wood-shuttered Heidi houses have proud geraniums trailing over their balconies. Golden cows graze velvet green fields. At the Viamala Gorge, the 17th-century Reichenau castle watches over the meeting arms of the River Rhine.

In the Domleschg Valley, forts and more castles enchant amid peaceful little villages set on tree-covered slopes beneath rocky peaks. Following the foaming waters of the Albula River, glacial green, fast flowing, white-crested in its speed, you enter the wild Schynschlucht gorge. There are ‘walls’ of tall pines and dark forests, steep drops, forbidding bare rock face, curtain waterfalls and glimpses of turquoise water far below.

To breach this seemingly impassable landscape, engineers faced steep mountain slopes and tumbling rocks to construct three bridges and 14 tunnels. The train bursts into light for mere seconds before plunging once more into darkness.

Emerging from the longest of the tunnels you are greeted by the flower-decorated, Swiss chalet-style station building at Solis. A few minutes later the train crosses the first of two spectacular viaducts.

The Solis Viaduct, at 540ft (164m) long and 295ft (90m) high, is the highest of all the bridges on the Rhätische Bahn network. The Landwasser Viaduct is perhaps the most elegant. With six graceful arches it curves high above a steep-sided river gorge, to end abruptly at a tunnel carved into sheer rockface.

At Filisur, a pretty railway junction village, an even more impressive journey begins as the track starts to climb steeply – 2300ft (700m) in 7.5 miles (12km). Two loop tunnels mean you see the village of Bergün three times from the steep slopes of Piz Ela before you arrive at its station.

On what has been called the most ingenious railway line ever built, the Bernina Express travels on a ‘spiral staircase’, twisting upwards through five loop tunnels, two normal tunnels, crossing nine viaducts and going under two galleries before reaching Preda, which lies at nearly 6000ft above sea level.

The journey continues through the Albula tunnel, Europe’s highest subterranean alpine crossing, into Switzerland’s Romansch-speaking Engadine region. Emerging from the tunnel, you may well find that the weather has changed. And, being at a watershed, the rivers are flowing in the opposite direction!

Through a long mountain valley, meadows, larch forests and cloud-raked peaks, the view from the train’s picture windows is peaceful. At Pontresina, a resort favoured by cross-country skiers, hikers and climbers, there’s a change of power supply, and soon sheer rock walls rise way out of view.

Suddenly you’re into an amphitheatre of snow-covered rock, looking at glaciers and surrounded by a gallery of mountains that peak at 13,000ft (4000m). Negotiating steep curves, the train climbs towards the Bernina Pass, travelling alongside the milky-green Lago Bianco, the White Lake.

The Bernina Pass, ‘land of eternal ice’, is a watershed – the rivers flow to the Po and into the Adriatic – and a linguistic boundary. South of the Pass, Italian dialects are spoken. At 7381ft (around 2250m) the station of Ospizio Bernina is the highest point on the journey.

Glaciers separate mountains and from Alp Grumm there’s a panoramic view of snowfields and a countless array of mountain peaks. Although Lake Poschiavo lies way below, it is hard to believe that in an hour’s time the train will be in Italy, in a Mediterranean climate among palm trees and flowering oleanders.

From the crest of the Bernina Pass, the train descends towards Poschiavo. Just 3 miles (5km) as the crow flies, but requiring a lot of curves to cope with the decrease in height of 3280ft (1000m). As the train twists and turns, there are views of the Poschiavo valley that sweeps between mountain folds.

Fields look spring-green bright, there are delicate harebells, mosses and grasses by the track. At Poschiavo station it’s time to alight. The border may be a few miles away, but this attractive little town with its piazza and pastel-painted buildings has a distinctly Italian air.

After a good lunch in Poschiavo take a local train this time, tracking up among the glaciers to St Moritz. Make time for a lakeside walk and window-shopping some of the multitude of designer name boutiques in the smart resort, before heading back to Chur.

From sunshine and geraniums, through layers of snow covered mountains, by glacier tongues and long-drop waterfalls, to green-swathed valleys and a taste of Italy all in three and a half hours – the Bernina Express journey is quite an experience. And a very comfortable one.

If the changing scenery is extreme and memorable, so too is the way the train deals with immense gradients, and with not a cogwheel or rack rail in sight. On the Bernina line the train climbs 228ft (70m) of height in every 3280ft (1000m) of distance covered. And down again.