Siling Co is the largest lake entirely within the Tibet Autonomous Region, covering more than 2,400 square kilometres at an altitude of 4,530 metres. It sits in the remote northern Chang Tang, roughly 300 kilometres west of Nagqu town, and requires considerable planning to reach — a hired vehicle, extra permits, and at least two days from the city. The effort is rewarded with a landscape of extraordinary scale and emptiness: turquoise water, flat grasslands, and the occasional herd of Tibetan antelope or kiang (wild ass).
The lake is saline and has no outlet, fed by streams and snowmelt from the surrounding ranges. Bird life is significant: bar-headed geese, black-necked cranes, and various species of wader breed along its shores. The surrounding grasslands are traditional winter pasture for nomadic herders, and small camps of yak-herding families are visible from the shore road.