About Green Lake & Zemu Glacier Trek
The Green Lake trek from Lachen to the glacier camp below Zemu Glacier is the most demanding and most rewarding trek in Sikkim — and one of the least known outside serious trekking circles. Zemu is the largest glacier in the Eastern Himalaya (26km long), and the approach from Lachen takes you through dense rhododendron and magnolia forest, across alpine meadows, and finally into the moraines beneath the glacier where the north face of Kanchenjunga (8,586m) fills the sky. Green Lake itself (4,200m) is a camp beside the glacial lake at the foot of Zemu — the point from which George Mallory, Paul Bauer and other early Everest-era mountaineers attempted Kanchenjunga from the Sikkimese side in the 1930s. The route requires a special trekking permit and takes 7–9 days return from Lachen. We Care Holidays runs this as a fully supported expedition with experienced local guides, porters and high-altitude camps.
Why go to Green Lake & Zemu Glacier Trek
Zemu Glacier and Kanchenjunga's north face
The largest glacier in the Eastern Himalaya. From Green Lake Camp the north wall of Kanchenjunga rises directly above you — the same view the 1930s pioneers had. Inaccessible by any other means than this trek.
The route of Mallory, Bauer and the Kanchenjunga pioneers
The German and British expeditions of the 1920s–1930s used this approach to attempt Kanchenjunga. Walking the same moraines with that context is a different experience from most Himalayan treks.
How to reach Green Lake & Zemu Glacier Trek from Lachen
Trek begins in Lachen. All arrangements (permits, porters, equipment) through We Care Holidays. Not a DIY trek — the permit process requires a registered operator.
Best time to visit Green Lake & Zemu Glacier Trek
April–May and September–October. The rhododendron forest is at its most spectacular in April–May. October gives the clearest views at high altitude. Avoid June–August (heavy rain on the lower forest section).
Time of dayMulti-day trek — start each day at 7am before afternoon cloud builds on the upper sections.
What you need to visit Green Lake & Zemu Glacier Trek
Green Lake Trek requires: North Sikkim PAP + Green Lake Special Trekking Permit + porters hired through a registered Sikkim operator. We Care Holidays manages the full permit and logistics process. Book at least 2 months in advance as permits are limited.
Things we always tell our guests about Green Lake & Zemu Glacier Trek
- This is a strenuous high-altitude trek — prior multi-day trekking experience is essential. Not suitable for first-time trekkers.
- The route crosses several high passes and moraine fields — waterproof trekking boots with ankle support are required.
- Altitude sickness precautions: acclimatise in Lachen (2,750m) for 2 nights minimum before starting.
- The trek is fully supported — we provide tents, meals and a high-altitude guide with wilderness first-aid training.
Green Lake & Zemu Glacier Trek — your questions answered
Other places in Lachen
- Sacred LakeValleyMonastery