Tilicho Lake is a glacial lake at 4,919 metres in the Annapurna range of central Nepal, one of the highest lakes of its size on Earth, turquoise and lifeless, with no fish and not even plankton in its cold water, under a wall of rock and ice rising to 7,134 metres. The lake is a side trip from the Annapurna Circuit, reached from the village of Manang in the high valley of the Marsyangdi, and the walk to it is the reason it is remembered: beyond the village of Khangsar the trail crosses a notorious slope of loose scree and shifting rock, timed for the frozen early hours when it holds firm, then climbs from the base camp lodge to the shore in three or four hours, the last of them on snow for much of the year. Then the lake, a sheet of turquoise in a bowl of grey rock and ice with Tilicho Peak's wall on the far side, and nothing moving on it.
The valley below is Manang, a district of old stone villages with carved prayer walls and Tibetan Buddhist monasteries, where the trek breaks for acclimatisation, and below base camp it opens into grazing meadows where yak herds move between glacial ponds. Hindus hold Tilicho to be the Kak Bhusundi lake of the Ramayana, where a wise crow-sage first told the epic's story to Garuda, the king of birds, and pilgrims come up in the summer. In 2000 three Russian divers descended into the frigid water in what stood for years as the highest scuba dive ever made, and found the bottom as empty as the surface. The lake is frozen most of the year and clear of ice from about June to October, and the trekking season is the autumn, when the air is dry and the sky over the Annapurnas is at its sharpest. Tilicho is a lake at the height of a mountain with nothing alive in it, and people climb for days to look at the colour.