Most of us neglect to factor trains into our usual idea of traveling – what, with car ownership a norm in most developed and developing nations. And of course, flying is a very popular option among the more financially-comfortable.
But what if you could take in the sights and sounds of dozens of countries in a series of trains, on a trip that lasts 21 days, spanning a whopping 18,755 kilometers?
A crazy idea but technically feasible.
Some wizards over at the r/MapPorn subreddit have managed to figure out the route for the (hypothetically) longest possible train journey in the world, stretching from Lagos in southern Portugal all the way to Singapore.

Reddit user posted a map detailing a specific route that would take travelers through 13 different countries, including Spain, Poland, Belarus, Mongolia, Vietnam, Thailand, and Malaysia, to name a few.
This route is only made possible due to the recent opening of a new line in Laos, dubbed the Boten–Vientiane railway, which connects Kunming, China to Vientiane, the capital of Laos.
Prior to the line's opening, however, travelers would have had to end their train journey in Vietnam, with a total coverage of 16,898 kilometers.
Including overnight stops.

The Boten-Vientiane railway opened on December 2, 2021. IMAGE: The Associated Press / Stuff
According to Mark Smith of seat61.com, a rail expert who assisted with trip calculations, the trip would technically take 21 days to complete, including several overnight stops to factor in the time needed to process documents like visas, as well as securing seats at connecting trains.
Some connecting trains also require leaving stations and traveling through various cities to get to the next train, located in a different station. Overall, the amount of money you'd need to spend on train tickets alone amounts to roughly US$1,350.
Yes, yes, it might still sound like a lot of money for us weaker-currency folks in Southeast Asia *haiya* – but of course, if you're from Singapore, this probably doesn't sound like much.
An added benefit of making this trip is the lower carbon footprint compared to flying from Portugal to Singapore. For example, if you were to take a flight from Lisbon, Portugal all the way to Singapore's Changi Airport, you'd be contributing to 1.67 tonnes of CO2 emissions.
Opting for this train ride would result with only 0.08 tonnes of CO2. As to whether this train journey is worth it for the greater good of the planet, that's really up to you to decide.
Things to keep in mind.

IMAGE: Reuters / Malay Mail
Reddit user u/htGoSEVe notes that the trip might not technically be possible at the moment, given certain border restrictions brought on by the COVID-19 pandemic.
This includes a specific train line from Lisbon, Portugal to Hendaye, France, which was suspended due to COVID-19, "but it doesn't look hopeful that it will ever come back."
Other Reddit users, like u/tancredi88, u/peksync, and u/Leo_ian, offered their own useful corrections to the train route, revealing that there isn't currently a train from Malaysia to Singapore, due to temporary service suspensions between Johor Bahru and Woodlands in the city state.
What does this mean for the people crazy and adventurous enough to take on this incredibly long train journey? You'll probably have to wait until travel restrictions are fully lifted.