Editor's Note — Monthly Ticket is a new CNN Travel series that spotlights some of the most fascinating topics in the travel world. In May, we're riding the rails as we explore the world's greatest train journeys. Whether you're looking for travel inspiration or insider knowledge, Monthly Ticket will take you there.
(CNN) — Free from the rigors of the daily commute, traveling by train is by far the most civilized way to get around and really get to know a new country.
We all have our favorite journeys, whether it's conquering the Alps on a cogwheel railway or streaking across the rooftops of Tokyo on a futuristic Shinkansen "bullet train."
And traveling by train is good for the planet, too.
"If all domestic and intra-EU flight routes that can be completed by train in less than four hours were replaced, 36 million tonnes worth of carbon emissions would be saved each year," Naren Shaam, founder and CEO of travel tech company Omio, tells CNN Travel.
"Trains are magical, and when I travel on one, I feel an immediate sense of calm as I gaze out the window. Trains are inclusive too, they adapt to everyone's needs and, if you're lucky, you can sit by a large window, daydream and enjoy the view.
Tempted? Here are 10 amazing trips every rail adventurer needs to cross off their to-do list once borders are fully open again.
West Highland Railway, Scotland
Magic ride: The West Highland Railway Line's Glenfinnan Viaduct appeared in the "Harry Potter" movies.
Regularly topping the charts as the world's favorite scenic rail journey, the outstanding West Highland Railway Line is a "greatest hits" of the best landscapes Scotland has to offer.
Running for about 193 kilometers (120 miles) from Glasgow to Fort William at the foot of Ben Nevis -- the UK's highest mountain -- it delivers an ever-changing panorama of lochs and glens, desolate moors and brooding mountains.
Not content with this, the line extends for a further 41 unforgettable miles (66 kilometers) to the west coast port of Mallaig, taking in some of the country's most beautiful lochs and the stunning curved viaduct at Glenfinnan, as featured in the "Harry Potter" movies.
The line can be enjoyed via the comfortable Caledonian Sleeper night train from London to Fort William, with the last stretch of the journey, across lonely Rannoch Moor, accompanied by breakfast. Remember to keep an eye out for stags, a Scottish icon, as they survey their kingdom.
Between April and October, the sleeper also connects with another famous train, the daily Jacobite steam train running from Fort William to Mallaig and back, offering the chance to enjoy the scenery at a leisurely pace on a beautifully restored piece of railway history.
Trans-Iranian Railway, Iran
The Trans-Iranian Railway's Veresk Bridge spans a deep gorge.
A little-known gem, this amazing feat of civil engineering was awarded UNESCO World Heritage Status in July 2021, giving it the same status as world-famous sites such as Machu Picchu and the Galapagos Islands.
Linking the Persian Gulf with the Caspian Sea, it opened in 1938 after 11 years of challenging construction. Although not widely known outside Iran today, it can legitimately claim to be one of the greatest engineering feats of the 20th century.
It runs for 1,394 kilometers (865 miles) from Bandar-e Emam Khomeyni on the Persian Gulf to Bandar Torkaman on the Caspian and passes through Ahvaz, Qom and Tehran on the way.
The railway features no fewer than 224 tunnels and almost 400 bridges as it climbs to 2,130-meter (7,000-foot) summits either side of Tehran.
Negotiating two formidable mountain ranges required not just the construction of long, steep gradients, but ingenious civil engineering to gain height via spiral tunnels and giant leaps over isolated valleys in fiercely hot, rugged terrain.
The result is one of the world's most memorable rail journeys, albeit one that few travelers outside of Iran have been able to enjoy.
The Ghan, Australia
Australia's legendary Ghan train is named after Afghan camel drivers who worked the country's interior in the 19th century.
Vast and hostile, the Australian Outback is not an environment to be taken lightly.
Fortunately, modern travelers can experience this astonishing landscape from the comfort of The Ghan. Widely regarded as one of the world's greatest rail journeys, it runs weekly over a 2,979-kilometer (1,851-mile) route spanning the length of Australia from Adelaide in the south, through Alice Springs and then to Darwin in the Northern Territory.
Each trip takes more than 53 hours, including extended stops at outposts such as Coober Pedy for passengers to experience the Outback during off-train tours.
Today's luxurious stainless steel carriages, which feature elegant dining cars and private cabins with personal attendants, are a far cry from the notoriously unreliable trains that plied the route between 1929 and 1980.
The origins of the train's unusual name are debatable, but hark back almost a century to its previous nickname "The Afghan Express" -- a reference to Afghan camel drivers brought to Australia by the British in the late-19th century to help open up the country's interior.
Qinghai-Tibet Railway, China
The Qinghai-Tibet Railway is sometimes called the "Railway to Heaven."
Sino Images/500px Asia/Getty Images
For centuries, the remote mountain plateau known as "The Roof of the World" was visited only by the hardiest travelers and explorers, but the opening of the remarkable Qinghai-Tibet Railway in 2006 created a permanent connection with the Chinese rail network.
Sometimes called the "Railway to Heaven," the 1,955-kilometer (1,215-mile) route from Xining in central China to Lhasa in Tibet tops out at the Tanggula Pass, 5,068 meters (16,627 feet) above sea level -- almost half of the line sits above 13,123 feet.
One of the greatest engineering feats of the early 21st century, the railway cost $4.2 billion to build. Challenges included building in a high-altitude region prone to earthquakes, with freezing temperatures, low atmospheric pressure and permafrost.
Unique pressurized carriages, designed specifically for the route, help travelers to minimize the effects of altitude sickness caused by the low oxygen levels on the world's highest railway.
Outside the train, travelers can enjoy amazing views of the fragile plateau environment, where yaks graze on grasslands dominated by the towering snow-capped mountains. Highlights include the Qiangtang Prairie, Kekexili Nature Reserve, Namtso Lake and the Tanggula Mountains at the highest point of the journey.
Direct trains run to Lhasa from Beijing in around 40 hours and Shanghai (47 hours) and from 2030, when the $47.8 billion Sichuan-Tibet Railway is complete, high-speed electric trains will reduce the 1,629-kilometer (1,012-mile) trip from Chengdu to Lhasa from 48 hours to just 13 hours.
Darjeeling Himalayan Railway, India
The Darjeeling Himalayan Railway is affectionately known as "The Toy Train."
Tuul & Bruno Morandi/Stockbyte Unreleased/Getty Images
Nicknamed "The Toy Train," this wheezing relic of the British Empire remains one of the world's greatest railway experiences. Climbing around 2,134 meters (7,000 feet) over a tortuous 89-kilometer (55-mile) route between New Jalpaiguri and the hill station of Darjeeling, the narrow gauge DHR uses every trick in the railway engineer's book to gain altitude.
Six zig-zags (where trains reverse several times to gain height) and five loops extend the railway's length, ensuring that the gradients are not too steep for trains to climb.
The railway was built in 1879-81 to improve access to the cooler mountain climate of Darjeeling in northeastern India, allowing the British colonizers to escape the stifling heat of Calcutta (now Kolkata).
It was declared a UNESCO World Heritage Site in 1998. Although much of the railway's traffic now moves by road, several trips a day operate, including the "Red Panda" tourist service from Darjeeling to Kurseong via the line's 2,258-meter (7,407-foot) summit at Ghum.
The line's most famous residents -- the legendary B-Class steam locomotives built between 1889 and 1925 -- still haul occasional special trains but most services are now hauled by diesels.
Oslo-Bergen Railway, Norway
The Oslo-Bergen railway passes through extreme highland landscapes.
Travelers in Scandinavia are spoiled for choice when it comes to scenic rail journeys, but the 496-kilometer (308-mile) trip between Norway's two largest cities is arguably the greatest of them all.
Linking Oslo with Bergen on the country's west coast, the Bergensbanen was completed in 1909 and crosses Europe's largest high mountain plateau -- the Hardangervidda.
Around the line's summit at Finse, the highland climate is so extreme that it was used by polar explorers such as Roald Amundsen and Ernest Shackleton to prepare for expeditions to Antarctica. More recently, the area was the backdrop for the famous snowy battle scenes in the "Star Wars" sequel "The Empire Strikes Back."
As well as the stark beauty of the highlands, travelers can enjoy unforgettable views of crystal clear lakes, rivers teeming with salmon, soaring mountains, the majestic Hardangerjøkulen glacier and, as the train approaches its destination, stunning fjords.
A magnet for winter sports fans, there are many other attractions all along the line, not least the world-famous Flåm Railway (another of the world's most incredible rail journeys), which descends steeply to the shore of the spectacular Sognefjord.
And as if that's not enough, the port city of Bergen -- gateway to the fjords and one of Norway's most popular tourist attractions -- is waiting for you at the end of your trip.
Bernina Express, Switzerland
Switzerland's Bernina Express connects the fancy alpine resort of St. Moritz with Tirano in Italy.
Simone Polattini/Adobe Stock
With its myriad mountain railways, cable cars, funiculars, post buses and lake steamers, Switzerland is like Disneyland for transport enthusiasts. With so many amazing journeys to choose from, it's difficult to pick a favorite. That said, the spectacular Bernina Express has to be high on any list of Swiss attractions.
Crossing the watershed where melting snow can run away to the North Sea, the Mediterranean or even the Black Sea, the Bernina Pass is the highest rail crossing in the Alps, following an ancient trade route.
But it's far more than that; it's a bridge between Northern and Southern Europe, linking different cultures, linguistic traditions and a transition from high mountains and glaciers of the Swiss canton of Graubünden to the palm trees and vineyards of Valtellina in Italy.
The immaculate red trains link the exclusive alpine resort of St. Moritz with Tirano in Italy, crossing the Bernina Pass at 2,253 meters (7,392 feet) above sea level. Panoramic trains with enormous windows make the trip several times a day. For a more immersive experience, take the all-stations regional train with its drop-down windows and breathe in the fresh, cool air of the mountains.
Every journey over the Bernina is different, whatever the season, but the highlights of any trip are the amazing spiral viaduct at Brusio, where the train crosses over itself on a tight curve, skirting around Lago Bianco near the line's summit and the final trundle through the streets of Tirano as you approach the end of the line. And remember, unlike most Swiss mountain railways, this is an international line so don't forget to bring your passport.
The Canadian, Canada
Canada's four-day train ride across a continent.
I Viewfinder/Adobe Stock
Railways were instrumental in the creation of some of the largest countries, opening up huge tracts of previously inaccessible land and linking farmland and forests with coastal cities and ports.
Canada is one of the greatest examples of the influence of railways, and its last remaining transcontinental train is a celebration of the country's breathtaking landscapes.
Over four days and 4,463 kilometers (2,775 miles), this train operated by VIA Rail connects Toronto with Vancouver via forests, lakes and seemingly endless prairies. But if you're heading west, the train saves the best for last as it climbs up and over the Rockies to reach its destination on the Pacific Coast.
In this age of instant communication and air travel, The Canadian is a throwback to a different time, where long-distance travel was more comfortable and more communal.
Sharing dining tables and open saloons over a longer trip allows you get to know your fellow passengers, enhance the experience and share stories as you travel. The train itself is a throwback, too, using beautiful 1950s stainless steel passenger and sleeper cars with spacious cabins and panoramic dome cars that offer a special window on Canada's amazing landscapes.
The Little Yellow Train, France
The Little Yellow Train (Train Jaune) provides a scenic view of the Pyrennees.
Leonid Andronov/iStockphoto/Getty Images
High in the Pyrenees, where the borders of France and Spain's Catalunya region become blurred, a spectacular and unusual railway climbs through narrow gorges and soars over deep valleys to reach the only French territory on the Iberian Peninsula.
Officially referred to as the Ligne de Cerdagne after the region it serves, it is more commonly known as "The Little Yellow Train" or even the "Metro of the Pyrenees" -- a nod to the origins of its pioneering early-20th century electric trains.
The most spectacular part of the 63-kilometer (39-mile) route is the climb away from Villefranche-de-Conflent, a superb fortified town and UNESCO World Heritage site 31 miles west of Perpignan, to Odeillo-Font-Romeu.
Hugging the sides of the deep, rocky valley of the River Tet, the line winds between forests, chasms and gushing streams, passing traditional villages, historic fortresses and a precariously perched hermitage.
Built from 1903 to 1909, the line is a spectacular feat of civil engineering, the highlight of which is the remarkable Pont Gisclard -- the only railway suspension bridge in France.
For fans of unusual railways, the old trains are worth the journey alone. In summer, they include open top cars that give an incredible 360-degree view and make this one of the world's best rail journeys. Seven of the 10 original trains, based on Paris Metro cars, are still in service.
From the summit of the line at Bolquère-Eyne, France's highest railway station at 1,593 meters (5,226 feet), the line winds its way across a sunny plateau past the frontier town of Bourg-Madame to La Tour-de-Carol, a very unusual station where the main line tracks of Spanish and French railways meet the yellow narrow gauge trains.
It may not be the most famous railway in the world, but you'll never forget your trip on this spectacular and quirky little train.
The TranzAlpine, New Zealand
TranzAlpine traverses Arthur's Pass on New Zealand's South Island.
Sebastian Nebel/EyeEm/Getty Images
New Zealand is far from ideal territory for trains, but it is home to what is undoubtedly one of the world's greatest railway journeys.
Linking the cosmopolitan city of Christchurch with Greymouth on NZ's South Island, the TranzAlpine takes four and a half hours to cover just 224 kilometers (139 miles).
But the bare statistics don't tell the real story of this incredible experience, which weaves through diverse landscapes ranging from the Canterbury Plains to the snow-capped mountains of the Southern Alps, remote alpine meadows and the lakes, streams and forests of the island's West Coast.
Swiss-style panoramic carriages allow you to make the most of this wonderful journey but the famous 'open air carriage' is the real highlight for many travelers. This open-sided car allows passengers to experience the fresh mountain air first-hand and capture New Zealand's amazing landscapes on camera.
For a richer experience, TranzAlpine passengers can also now listen to a GPS-triggered audio commentary in English and Mandarin, sharing stories and facts about places along the route, the country and its culture.