The sleeper train is a comfortable, convenient, and timeless way to travel between Hanoi and Sapa. Note that trains terminate in Lao Cai, which is an hour's drive from Sapa. You can book a comfortable soft bed in a shared 4-berth cabin online. To reconfirm your ticket, you'll need to be at the station an hour before the train departs. You can book your ticket online through this convenient ticketing service.