Nepal has a  number of the remote areas , which  were restricted for foreign visitors until 1991 where the entry of foreigners is strictly controlled. These trekking areas are different in many features from ordinary ones. Many treks that may be suggested on a map are in restricted areas and you either can not get a permit for these areas. You must travel with pay for a special permit. Groups must consist of a minimum of two clients and the required staffs. The main objective of declaring these areas ' restricted' is to protect the natural environment and culture from outside influences. The environmental officer has to handle all the formalities with the police and government offices in route. The treks must be fully arranged through registered Trekking Company. It has to be fully equipped with tent, all Support staffs, cooks, etc. The trekking agency arranges the trekking permit through a series of applications and guarantees letters. You cannot trek along in the restricted area, such as Upper Mustang, Upper dolpo, Lower Dolpo, Manaslu, Kanchenjunga, Rolwaling and Humla - Simikot etc…