Nanda Devi is the second highest mountain in India, and the highest entirely within the country. (Kangchenjunga, on the border of India and Nepal, is the highest peak in India.Nanda Devi is a two-peaked massif, forming a 2 kilometres (1.2 mi) long high ridge, oriented east-west. The west summit is higher, and the eastern summit is called Nanda Devi East

After the re-opening of the Sanctuary in 1974 to foreign climbers, trekkers, and locals, the fragile ecosystem was soon compromised by firewood cutting, garbage, and grazing. Serious environmental problems were noted as early as 1977, and the sanctuary was closed in 1983. Currently, Nanda Devi forms the core of the Nanda Devi Biosphere Reserve (which includes Nanda Devi National Park), declared by the Indian government in 1982. In 1988, Nanda Devi National Park was declared a UNESCO World Heritage Site, of outstanding cultural or natural importance to the common heritage of humankind.