Lanzhou is a good one-night stop, and the stations are far apart

One night is the right dose: noodles, the museum, the iron bridge at dusk and the night market on Zhengning Road. Then move on.

Lanzhou West takes the high-speed services — Xi'an about three hours, Xining one, Zhangye three — while the old Lanzhou station in the centre serves slower trains, including some of the Dunhuang sleepers. They are a long way apart, so check your ticket the night before and leave 40 minutes to cross the city.