A very, very different part of Nepal and for many years an area where foreigners were not allowed to visit, the former Kingdom of Mustang remains a restricted area. Indeed, the permit costs and the relentless, inescapable high altude deter many. To the adventurous, intrepid and informed traveller with a good level of fitness and previous experience trekking at high altitude,  such barriers and the opportunity to trek without the crowds are likely to be more of an attraction. Indeed this land 'behind the Himalaya' is culturally and geographically a part of Tibet. The monsoon doesn't really reach Mustang and so the landscape is almost 'Martian'. Arid and barren, with weird wind eroded rock formations and cliffs. There is much beauty too, particularly the pigmented colourations of  the landscape-ochre, brown, grey, red, yellow and dotted with tiny, traditional Tibetan style villages just able to eek a life in this often inhospitable region. The 'jewel' of Mustang for many is the fabled, walled 'city' of Lo Manthang. With the encroachment of a jeep road and the compromising effect that has on the sensation of wild trekking, we have designed this itinerary to avoid it as much as possible and use it only where it is unavoidable. During some of the main Nepal trekking season it's way too cold to trek in Mustang and the winter (November to February) months are to be avoided. However, as the monsoon does not reach most of Mustang, this is a trek that can actually be undertaken during the summer months too. Don't forget our trekking holidays are tailor-made and you may wish to consider more acclimatisation days, rest, contingency days added.  The itinerary is merely a suggested itinerary and is not entirely  'set in stone'. Sleeping bags (4 season) will be required for nights spent in trekking lodges/teahouses. We can arrange sleeping bag  rental if required.