Qinghai Lake, formerly known as Koko Nur or Kukunor, is a saline and alkaline lake situated on the Tibetan Plateau in the province of Qinghai, and is the largest lake in China. The names Qinghai and Koko Nur both mean "Blue/Teal Sea/Lake" in Chinese and Mongolian. It is located about 100 kilometres (62 mi) west of the provincial capital of Xining at 3,205 m (10,515 feet) above sea level in a depression of the Tibetan Plateau in the cultural area known to ethnic Tibetans as Amdo. Twenty-three rivers and streams empty into Qinghai Lake, most of them seasonal. The lake has fluctuated in size, shrinking over much of the 20th century, but increasing since 2004. Despite its salinity, it has an abundance of fish, such as the edible naked carp.
The lake is also sometimes circumambulated by pilgrims from the region. Przhevalsky estimated it would take about 8 days by horse or 15 walking to circumambulate the lake, but pilgrims report it takes about 18 days on horseback, and one took 23 days walking to complete the circuit.