The best time to travel along the road traversing the Song Chay valley between Bac Ha and Tan Quan is a Sunday, when fairs and markets are held in Lung Phinh, Xin Man and Hoang Su Phi. Between Bac Ha and Tan Quang, small groups of men and women in colourful costume sell their wares. Be careful: the road is grandiose but in an appalling condition from Lung Phinh on. Get the latest information before setting out.