Langtang Region is one of the most unspoiled national parks of Nepal which is situated north of Kathmandu near the Tibetan border; it is the most easily accessible highland sanctuary from the capital. Langtang covers 1,710 sq. kilometers forming the upper catchments areas of two of Nepal's largest river systems - the Trishuli and Koshi. This National park was designed in 1970/1971 but established only in 1976 by the government of Nepal. The three major areas are Langtang, Gosainkund and Helambu, which can be combined in many different ways to make treks from 7 to 16 days long. This trekking route requires a national park permit and it is illegal to enter inside the national park without national park entry permit.