The southern route, a well-surfaced highway running parallel to the Himalayas all the way to Western Tibet’s main town, ALI (also known as Shiquanhe), passes through Saga, and on to Darchen, and makes for a stunningly picturesque journey. From Lhasa to Mount Kailash is around 1400km.
The alternative northern route via Tsochen, Gertse and Gakyi is longer: it’s over 1700km to Ali, and then another 300km or so southeast to Mount Kailash. It is also less scenic, but less liable to be affected by snow or flooding. Some tours plan to go on one route and return on the other – expect around a week’s-travelling time on either.