Train Guide to Vietnam
The principal route in Vietnam is the 1,727 km (1,100 mi) single-track North–South Railway line, running between Hanoi and Ho Chi Minh City. This was built at the metre gauge in the 1880s during the French colonial rule. There are also standard gauge lines running from Hanoi to the People’s Republic of China, eventually leading to Beijing, and some mixed gauge in and around Hanoi. The 29-34-hour passenger trip between Hanoi and Ho Chi Minh City is very popular both with locals and foreign visitors. Accommodations are: hard seat, soft seat, 4 berth sleeper, and 6 berth sleeper. Coastal resorts such as Huế, Hội An, and Nha Trang lie along the route and generate considerable tourist traffic. In the border region, the Sapa line to the north is a very popular tourist attraction, with first class accommodations available. East of Hanoi, the line is dual gauge, with through trains to China available. Visas are required to book cross-border trains. The Ho Chi Minh City–Hanoi line has been rebuilt and upgraded, and damage from war has been repaired. – Wiki
I haven’t been on the trains in Vietnam yet. My plan is to go in March 2023. For the time being I will be adding notes and links to help with my own trip. I will then add photos and more details once I am back.