Thorong La is the high point of the Annapurna Circuit — a crossing at 5,416m that most trekkers approach with a mixture of excitement and anxiety. The ascent begins from High Camp (4,925m), usually starting between 3 and 5 in the morning. The first hour of climbing in the dark, with headtorches bobbing ahead and behind on the steep trail, is both brutal and exhilarating. The summit, marked by prayer flags and a stone cairn, is reached after three to five hours of climbing.
On a clear day, the views from the summit are extraordinary: south over the Marsyangdi Valley and the peaks above Manang, north towards Mustang and the brown hills of Tibet. The descent to Muktinath (3,760m) drops over 1,600m in about four hours on a loose, knee-punishing trail — trekking poles are strongly recommended. Most people stop for tea and daal bhat in the small settlement at Charabu before the final hour into Muktinath town.
Altitude sickness is the main danger. The standard advice is to spend two nights in Manang for acclimatisation, and to not ascend more than 300–500m of sleeping altitude per day in the lead-up. If you develop a severe headache, vomiting, confusion, or ataxia, descend immediately regardless of the time or conditions.