Mustang
The old walled kingdom of Lo, behind the Himalaya in the rain shadow — and the one great trek that works in the monsoon.
Upper Mustang sits north of the main Himalayan wall, which means it is dry when the rest of Nepal is under water. Culturally and geologically it belongs to the Tibetan plateau: red cliffs, wind, caves cut into the rock face, and whitewashed villages around a gompa.
The walking is not especially high by Nepali standards and rarely steep, but it is exposed and the wind gets up every afternoon. The destination is Lo Manthang, a walled town with a royal palace and monasteries that were painted centuries ago.
Stamina rather than lungs, and planning. This is a restricted area with an expensive per-person permit issued for fixed dates, a compulsory licensed guide and a minimum of two trekkers. It needs arranging well in advance.
March to November, and uniquely, the monsoon months are among the best — green barley against red rock, and almost nobody there.
