Langtang National Park was established in 1976 as Nepal's first Himalayan national park and the country's fourth protected area. It exceeds an elevation range of and covers an area of in the Nuwakot, Rasuwa and Sindhulpalchok Districts of the central Himalayan region. It encompasses 26 village communities and includes the Langtang valley. In the north and east it is linked with Qomolangma National Nature Preserve in the Tibet Autonomous Region.
The eastern and western boundaries follow the Bhote Koshi and the Trishuli river, respectively. The southern border lies north of the Kathmandu Valley.
The Gosainkunda lake is located at an elevation of inside the park. The Dorje Lakpa range at bisects the park from west–east to south–east. The summit of Langtang Lirung () is the highest point in the park.
Langtang National Park is part of the Sacred Himalayan Landscape.
In 1970, royal approval designated the establishment of Langtang National Park as the first protect