Sikkim is a small mountainous state in northeastern India. It borders Tibet, Bhutan, Nepal, and West Bengal. Sikkim has a population of over 600,000 people and is known for its biodiversity and being home to the Kangchenjunga mountain. The state has four districts and the traditional costumes of the main ethnic groups, the Lepchas and Bhutias, include dresses, cloaks, and heavy gold jewelry for women. Sikkimese is the main language spoken and belongs to the Tibeto-Burman family; it was not a written language until 1975. The region celebrates many festivals throughout the year according to the Buddhist calendar with dancing and music.