Trans-Vietnam railway among world's most incredible train journeys: Lonely Planet

The railway stretches for more than 1,726 kilometers between the country's two biggest cities of Hanoi and Ho Chi Minh City over the course of two days.

"Some railways rattle through historic cities; others swoosh beside spectacular coastlines. A few have an epic history, and one or two are remarkable for the colorful characters onboard. The Reunification Express line fulfills all these criteria," said Lonely Planet.

The site also stressed that travelers cannot find a more atmospheric way to travel between Vietnam's two metropolises. "And there's no better way of exploring all the glories in between," it concluded.

The journey allows passengers to sit and enjoy romantic scenery and rural landscapes along coastal towns in the central region, including the former imperial capital of Hue, the Da Nang City Port which was initially built in the French colonial period, and the ancient town of Hoi An.

Other train journeys in the list are the California Zephyr of the U.S., Lake Titicaca Railway of Peru, Lhasa Express of China, Caledonian Sleeper of the U.K., Bergensbanen of Norway, TranzAlpine of New Zealand, and Tazara Railway of Tanzania and Zambia.