This is how you go about it:
- take an overnight train from Hanoi railway station to Lau Cai near the Chinese border
- arrive in Lau Cai early the next morning
- mini-vans wait outside station to ferry you to Sapa
- the road up to Sapa is winding but the terraced slopes for crop cultivation provide some distraction.
In winter, Sapa can be very cold while in summer the weather is perfect.