Some commentators report the slow death of the sleeper train. They claim that the venerable services that meander through the European night have all but disappeared.

Which would be a shame. That final whistle before you bed down then snake through Scotland, Spain or Siberia harks back to the civilised days of travel. It’s bettered only by waking up for breakfast in a brand-new country: along the French Riviera, overlooking the Grand Canal or beside the mighty Bosphorus.

Sure, as the continent’s network speeds up, some traditional routes have been replaced by bullet trains. For example, the Paris-Barcelona route now takes just over six hours (two years ago it was 12), allowing guests to breakfast in St Pancras, lunch on steak-frites, then take tapas on the Med. In Helsinki, one may blast past the pack ice to St Petersburg in three and a half hours. Last year the Istanbul-Ankara sleeper service was swapped with a high-speed train boasting seat-back TVs. It’s now four hours, not nine hours, door-to-door.

But in other areas sleeper trains are back on track. A new breed of long-distance commuter services has brought business class to the rails. German operator Deutsche Bahn’s City Night Line service and Spanish rail company RENFE's Trenhotel are literally hotels on wheels. On board expect en-suite showers, luxury linen and fine dining.

That final whistle before you bed down then snake through Scotland, Spain or Siberia harks back to the civilised days of travel Photo: AP/FOTOLIA

They also have chic cabins that lock with a hotel-style swipe card. This allows passengers to pop to the lounge bar for a beer as they glide from Munich to Rome or Frankfurt to Prague. They certainly pip easyJet and Ryanair in the stress stakes and – when booked in advance – on price too.

Other services, like the London to Penzance sleeper, have been saved from the ravages of railway cuts, not to mention the 2014 floods, which destroyed part of the track at Dawlish. This service is England’s finest: guests may use the First Class Lounge at Paddington, then are woken up with a bacon sandwich in sunny Cornwall.

The London to Penzance sleeper has been saved from the ravages of railway cuts, not to mention the 2014 floods, which destroyed part of the track at Dawlish Photo: AP/FOTOLIA

Finally, for those who can afford it, a dozen private trains now criss-cross Europe. On the Royal Scotsman, Spain's El Transcantabrico and the Venice Simplon-Orient-Express, one expects Hercule Poirot to rock up any minute clutching a silver cheese knife and a pocket watch.

For those one lower budgets, head east. Turkey’s superb sleeper service now radiates out from Ankara. Think private cabins with your own writing table, picture window, fridge and sink. Köfte meatballs are dished up in the dining car down the hall – and all for the price of a return ticket on the Gatwick Express. Other new sleeper services are now depart from Sofia, Budapest and Lviv.

The Royal Scotsman operates from late April to late October Photo: ROYAL SCOTSMAN

A final factor in the enduring popularity of sleeper train travel isn’t price, comfort or the avoidance of airport security. It’s the ease of booking. Family-size cabins to Southern Italy or the Spanish Costas may now be reserved – in English – in just a few clicks. For bespoke trips specialist rail and hotel booking agencies like Railbookers (020 3327 2420, www.railbookers.com) or Great Rail Independent (01904 527181, www.greatrail.com) act like a telesales version of Thomas Cook. Worldly staff can tailor rail tours from London to Marrakech or around Andalucía, hand-delivering tickets to your door.

Hopping aboard any of these top 10 long-distance train journeys is like turning the clock back to a golden age of rail travel. Each one proves that getting there is at least half the fun.