Nepal has various trekking routes and trekkers should have different trekking permits to explore the regions accordingly. Nepalese government has declared open trekking regions, controlled trekking regions and restricted trekking regions in Nepal.
The trekking regions where trekkers must join with government registered agencies to obtain trekking permits and must have government registered license holder guide to trek is called restricted trekking area. This means trekkers are not allowed to trek their own such as Manaslu Region, Nar Phu, Upper Mustang, Kanchenjungha, Dolpo, Mugu, Simikot etc. Minimum 2 trekkers with valid passport and visa are mandatory to obtain such an areas trekking permits and trek.
There are many reasons why the restricted areas exist. Since we have open border with Tibet and keep balancing political relation with China, preserving most valuable flora fauna and mines are the strongest factor of restricted areas declaration. In most cases, it is an unstable situation from a time when the border with China was more sensitive than it is now. Environmental groups, particularly the Nepal Nature Conservation Society are pressuring the government to keep some places closed for ecological reasons to avoid both cultural and environmental degradation. Because trekkers require assistance when something goes wrong (accident, illness or theft), the government restricts some areas because it doubts that it could provide the security that trekkers need.
There are many influences on the decision to open or close certain parts of Nepal to foreigners. Recent changes have liberalized both trekking and climbing and there is considerable pressure to open more areas to trekkers. You should check with a trekking agencies like Nepal Trekking Experts or the central immigration office before planning an unusual trek.
The Everest-Khumbu region is situated in the northeast of Nepal and is home of course to the world's highest mountain, Everest, soaring up to a daunting altitude of 8848 meters. Other Himalayan giants standing at over 8000 meters are also to be found in the area, including Lhotse, Makalu, and Ch Oyu. The region is home to Sagarmatha National Park and features some of the finest trekking in Nepal, as well as some of the most difficult. Hiking to the foot of such a legendary mountain is both awe-inspiring and humbling - and certainly one to be savored.
To the far northeast lies yet another giant, the third largest mountain in the world, Mt. Kanchenjunga (8586m). The region borders both India and Tibet and encompasses a unique conservation area, a tri-national peace park bordering three nations. It was opened to trekking in 1988 and includes pristine routes that offer spectacular scenery, abundant wildlife, and rich cultural diversity, as well as dramatic views of Everest, Lhotse, Makalu, and of course the mighty Kanchenjunga itself.
Situated in the central-west of Nepal lies the Manaslu region, home to the world's eighth highest peak (8156m) of the same name as well as the equally impressive and holy mountain of Ganesh Himal (7406m) and Himalchuli (7893m). The region was closed off to trekking through to 1991 in order to protect the fragile environment and cultural heritage of the area. Since its opening to the outside world it has become increasingly popular and is now regarding as one of the premier trekking destinations in Nepal due to its stunning scenery, unique culture and pristine wilderness.
The Annapurna region has long been one of Nepal's most popular trekking areas, with easy access from the major trekking hub of Pokhara, which is close at hand. Rivaling Everest for the sheer scale of its many soaring peaks, the Annapurna massif not only encompasses the eponymous and deadly peak that stands at an altitude of 8091 meters, but a range of 13 other mountains that soar over the 7000 meter mark. Not only does the area lay claim to some of the best trekking routes in the Himalayas, it's also home to the world's highest body of water, Lake Tilicho, which lies at 4919 meters above sea level.
Just north of Kathmandu lies the Langtang Valley, another region that has been very popular with trekkers through the years. Home to some of Nepal's most beautiful and diverse scenery Langtang is also renowned for its diverse cultures, people of widely disparate belief systems who live harmoniously in the region. For those seeking serene hiking, beautiful scenery and a range of options for extending their journey, Langtang is a perfect choice.
Formerly the ancient kingdom of Lo, Mustang has only been opened to the outside world on a restricted basis since 1992, and is located to the north of Annapurna on the same plateau that it shares with Tibet to the north. Home to the highly unique Tibet communities who have lived in the region for centuries, the area offers an extraordinary perspective on the time capsule of ancient Buddhist traditions and religious customs that have been carefully preserved through limited access. Sheltered from the monsoon rains of the Indian plains by the Annapurna massif, the Mustang region differs markedly from the southern trekking regions insofar as being a highly arid desert landscape of stratified outcrops and deeply eroded canyons that bear a closer comparison to Tibet than the rest of Nepal. So if you're looking for a walk back through time culturally and highly unique and isolated landscape the Mustang region may be the ideal choice for you.
Founded in 1979, Rara National Park is named for the beautiful lake at its heart, the largest in all of Nepal. Situated at an altitude of 2990 meters above sea level, the park and its abundant forests were established in the main to not only preserve the lake's extraordinary beauty and magical setting but also as a key staging point for migratory bird species, many of them rare. The park's diverse range of wildlife and flora makes it one of Asia's most important biospheres and provides limitless possibilities for eco-tourism amidst some of Nepal's most stunning landscapes.
Dolpo, like Mustang, is a remote high altitude region of Nepal that's a unique preserve of Tibetan culture that's remained largely untouched by outside influences thanks in no small part to its inaccessibility and the trekking restrictions that forbade entry until little more than twenty years ago.
An area renowned for its extraordinary beauty, rugged treks, and high altitudes, Dolpo exists as two distinct regions, the upper section situated on the Tibetan plateau that's essentially a high altitude desertscape, and the lower part which is heavily forested and the site for the serene beauty of mountain-locked Phoksundo lake. The vast majority of sparsely populated Dolpo lies at an altitude in excess of 3500 meters and is home to some of the world's highest communities and a nomadic people still living out an existence that has remained largely unchanged for centuries.