Along with an Indian Visa, foreigners are required to obtain Inner Line permits for Sikkim, which are valid for 15 days which can be extended for a further 15 days once in Sikkim. However no special permits are required for travelling to Darjeeling & Kalimpong. The permits are available at all Indian Missions / Consulates abroad and Sikkim Tourism Offices at Delhi, Calcutta, Siliguri and Gangtok.