Upper Mustang Trek
Permits & Regulations:
All trekkers heading into Upper Mustang (north of Kagbeni) are required to purchase a $500 per person permit, which is valid for 10 days. You can stay longer, but every day after that will cost $50. At Kagbeni, you'll be required to show your permit both on the way and the way out. In addition to the restricted permit, you'll also need to purchase an Annapurna Conservation Area Permit (ACAP), which is $20 USD per person.
Upper Mustang lies in the rain shadow of the Himalaya, making it a great monsoon trek and open year-round for trekking. The main consideration is the winter, when most residents leave the capital to avoid the cold and snow. Generally, the best time to visit Upper Mustang is from March to early November