Upper Mustang trekking is one of the most popular trekking destination for the trekkers or travelers to explore remote areas, natural caves, Buddhist monasteries and superb landscapes. We would like to say this region is forbidden kingdom with ancient walled-city of Mustang. Upper Mustang is opened for foreigners since 1992. All kinds of trekkers find this region is really enjoyable by the grace of its beautiful natural landscapes and isolation. Upper Mustang is an ancient Himalayan kingdom, lies to the north of Nepal, is still considered and to be said but where beauty and happiness exist in spite of hardship. This region is also considered as one of the most interesting and picturesque place in Nepal consisting of two distinct regions southern and northern part where the tradition, language and culture are alike to Tibetan people. The upper mustang, one of the Buddhists kingdoms, inspires to visitors to make a trip in remaining life in this region. According to the history of Tourism in Nepal, only handful tourists had visited in this region before opening tourism in 1992. The place with white snow-capped mountains and barren hills reach deep inside the vast Tibetan plateau. Strong and cold winds sweep through narrow canyons and over plains. All kinds of bizarre marks and forms are left with its bizarre creations. But it lies in two big and high mountains: Annapurna and Dhaulagiri which are more than 8000m high with living humans in hostile environment for centuries. The people who live in the region, have built their settlements along the rivers and creeks, the white-washed buildings appear like oases in the big desert. Cultivating and harvesting potatoes, wheat, barley, oat, vegetables and driving domestic animals to relatively fertile meadows. Amepal had founded the independent kingdom of Lo was in 15th century. Probably, it was big grace to its remoteness that even in later of conquest of mustang was granted as large autonomy. As the Hindu cultures are definitively a threat those days, the destructions of their culture and religion could be averted. So, finally, in 1950, it was officially declared the part of Nepal. The years following, the Chinese invasion of Tibet proved to be the most difficult ones in the history of Mustang. It was attacked nearby the large numbers of Tibetan freedom fighters. Putting Nepal in a delicate situation. Finally, recent Dalai Lama asked the guerillas to stop fighting, as well as the Nepalese government had sentenced some of the leaders. So, some of those efforts have helped discovering the scenic and cultural beauties and mysteries in the area.