Sikkim, four districts and three permit systems.

Sikkim is India's second-smallest state and it points almost straight up: from 300 m in the south to Kanchenjunga at 8,586 m on the Nepal border. It was an independent kingdom until 1975, and the Buddhist monasteries, Lepcha and Bhutia villages and Nepali-speaking towns all sit in that history.

What that means practically is that the state's best landscapes — Nathula, Tsomgo, Yumthang, Gurudongmar — are close to a sensitive border, so access runs through restricted-area permits rather than open roads.

In Sikkim, the itinerary is a paperwork problem before it is a travel problem. Sort the permits and the rest is a drive.

Foreign nationals need a Restricted Area Permit (the Inner Line Permit) for Sikkim itself. Since January 2026 this must be obtained online through the central e-FRRO portal before you arrive — the paper permits once issued at Rangpo and Melli have been discontinued. It is free and valid 30 days. OCI cardholders are not exempt.

Tsomgo Lake, Baba Mandir, Nathula and all of North Sikkim need a Protected Area Permit — Indian nationals included — arranged through a registered Gangtok agency with original ID. Aadhaar is not accepted; carry a voter ID, passport or driving licence plus two photographs. Nathula is open to Indian nationals only, Wednesday to Sunday (closed Monday and Tuesday). Gurudongmar Lake and Zuluk are closed to foreign nationals entirely, and foreigners must travel in a group of two or more with a registered guide. Permits name a fixed route, so the itinerary is approved in advance rather than improvised.

North Sikkim — Lachen, Lachung, Yumthang, Gurudongmar — also needs a permit and can only be done with a registered vehicle and driver. In practice you book a three-day North Sikkim package; independent driving is not permitted. Gurudongmar is closed to foreign nationals.

Gurudongmar sits at about 17,800 ft and you reach it from Lachen at 8,800 ft in a single morning drive. That is a fast gain, and headaches, nausea and breathlessness are common at the lake.

Keep the visit short, don't run around at the top, drink far more water than feels necessary, skip alcohol at Lachen, and turn back if symptoms build. Anyone with a heart or lung condition should talk to a doctor before committing to this leg.

Proper cold-weather layers for the north — Gurudongmar and Nathula are freezing and windy in any season — plus gloves, a hat and sunglasses for snow glare.

Add a refillable bottle, cash (ATMs thin out past Gangtok), a power bank, motion-sickness tablets for the switchbacks, and any altitude medication your doctor recommends.