The reason most travellers ever come to Golmud. Trains to Lhasa, to Xining, and onward into the rest of the Chinese rail network all leave from here. The station is large, modern, and well kept; the platform is at 2,800 metres, the highest you will be until the climb begins.
The Lhasa-bound train is the one to take. It departs Golmud in the late afternoon, climbs onto the plateau through the night, and reaches the Tanggula pass at dawn — 5,072 metres, the highest point of any railway anywhere. Oxygen is piped into the carriages. Book a soft sleeper if you can; the lower berths fill quickly. Foreign travellers must show a Tibet Travel Permit at the gate.