As of early 2026, the longest train journey starting in Portugal is a record-breaking odyssey from Lagos (in the south) or Lisbon all the way to Singapore. This staggering route covers approximately 18,755 kilometers (over 11,600 miles) and takes roughly 21 days to complete. It is not a single continuous train but a carefully stitched-together series of rail networks across two continents and 13 countries, including Spain, France, Germany, Poland, Russia, Mongolia, China, Laos, Thailand, and Malaysia. The journey was made possible by the recent completion of the high-speed rail link through Laos, connecting the Chinese network to Southeast Asia. Travelers witness a shifting panorama from the Atlantic coast of Europe, through the vast Trans-Siberian expanse, and down into the tropical jungles of Southeast Asia. Costing around $1,350, it requires significant planning for at least seven different visas but is hailed by rail enthusiasts as the ultimate "slow travel" experience, providing a perspective on the world's borders that a three-hour flight simply cannot match.