The mind boggles. I’m on a train that clings improbably to a vertiginous mountainside, gazing at another dizzyingly located line notched into the opposite flank of the gorge, wondering where on Earth it goes to. Perhaps the internet will know.
Google tells me it’s where my train has just been. But that would be sorcery, surely: the other track is far higher and I haven’t detected any downhill segments. The data-centre brain insists there’s only one route in this valley. An engineering sleight-of-hand is occurring; within a tunnel inside the rockface, the line opposite spirals 360 degrees before popping out lower down and crossing the ravine to continue southwards.
Say bonjour to France’s most spectacular commuter service, marketed for tourists as le Train des Merveilles – the Train of Wonders. It lives up to the hype, yet remains a well-kept secret – even in France. My French partner, Gersende, polls 19 of her French-born friends on WhatsApp and asks if they’ve heard of the line. Only three say “oui”.
“Now I want to know more,” says one.
Allow me to oblige. Reopened on 15 December, 2025, after 15 months of storm-damage repair work costing £63m, the Train of Wonders line runs from Nice-Ville station on the Côte d’Azur to the higgledy-piggledy medieval Alpine town of Tende in the Roya Valley, about 10 kilometres (six miles) from the Italian border as the local bearded vulture flies.
It’s a perfectly doable day trip from the coast – and great value. For just €20 (£17), you can hop on the 9.32am service (enjoying live onboard commentary between April and October), arrive in Tende at 11.32am, spend a few hours exploring, then take the 3.02pm back to Nice in time for dinner.
My introduction to the service, however, begins in Tende, beneath bruised August skies. Gersende, our nine-year-old daughter and I board one of up to eight daily trains that are a vital link for valley residents to the coast, and a holiday highlight for tourists in the know.
We pay just €40 between us (about £11 each) for a return ride in almost empty air-conditioned trains to the village of Breil-sur-Roya. It’s only 24 kilometres (15 miles) away, but the train takes 45 minutes to get there, at an average speed of 32 kilometres per hour (20mph).
France has a well-known forte for fast trains but, like Gersende’s friends, I had no idea until this journey that it has a gravity-defying Switzerland-style scenic line up its sleeve, too.
It was inaugurated in 1928 as a game-changing upgrade to the region’s treacherous mule tracks and remains an impressive feat of engineering. Including spurs to Ventimiglia on the Italian Riviera and Cuneo in the Italian Alps beyond Tende (run by Italy’s Trenitalia), there are 81 tunnels, 400 or so bridges and four spiral loop tunnels.
The Tende to Breil-sur-Roya stretch – a descent from 824 metres to 306 metres – is the most intensely picturesque of the 143 kilometre-network (88 miles).
To catch the best views, I flit from one side of the carriage to another like a hyped-up canary in a cage. The handful of locals in nearby seats stare at their phones and pay no attention to me gasping at the geology and pointing at teetering villages.
We inch away from Tende across a sweeping viaduct, with views of the town’s centuries-old buildings giving way to wilderness. Above: tree-covered peaks of limestone and dolomite; below: the Roya river, churning through the canyon alongside the Med-to-mountain main road.
We pass through two spiral loop tunnels, which soften the descents imperceptibly and spin my internal compass. The stops include Fontan-Saorge, which serves lofty Saorge, an official “Beaux Village de France” (Beautiful Village of France) hugging a rockface.
At Breil-sur-Roya, where connections to Italy can be caught, we admire the rustic five-storey townhouses before heading back to Tende to explore its beguiling honeycomb of ancient lanes and alleyways. We climb up to the hillside cemetery, which affords magnificent views of trains trundling over the viaduct.
Tende makes a superb base for exploring this pocket of France, which includes the 1,999 square-kilometre (772 square-mile) Mercantour National Park. We stay at Hotel Chamois d’Or in nearby Casterino, on the border of this beautiful expanse, and feel like extras in The Sound of Music as we hike its biodiverse forests and meadows to a backing track of whistling marmots.
As end-of-line destinations go, it takes some beating, and it has the stamp of approval from Azuréens; hotel guests from Nice tell me the area is a lovely place to cool down during the furnace-like summer. Train of Wonders? Yes, in so many ways.
How to get there
Travelling from London to Nice by train takes about 10 hours with two changes. easyJet, Ryanair and British Airways all fly from the UK to Nice. Tende is about an hour’s drive north, or two hours aboard the Train of Wonders.
Where to stay
Hotel Chamois d’Or, Casterino, has doubles from about £120.
More information