Tianshuihai[2][3] (Chinese: 甜水海; pinyin: Tiánshuǐ hǎi), alternately spelled Tien Shui Hai,[4] is a salt water lake in the disputed Aksai Chin region administered by China as part of the Xinjiang Autonomous Region (Hotan County, Hotan Prefecture),[5] which is also claimed by India.

[11] The Tianshuihai basin (or Thaldat basin) is at the northeastern corner of the Lokzhung Range of hills, which divide the Aksai Chin region into two distinct halves (called Lingzithang Plains and Kuenlun Plains by geologist Frederic Drew).

[12][13] The lake is said to drain a very large area, via the Thaldat stream that flows through the Lokzhung Range in a northeasterly direction.

[6] However, on the western edge of the plain, at the foot of Lokzhung hills, patches of vegetation were reported by Henry Cayley, who explored the area as the British Joint Commissioner in Ladakh.

[14] Drew reported kyang (Tibetan wild ass) frequenting the basin, which was seen to be their watering place.

[18] In 1865, the surveyor W. H. Johnson surveyed the Aksai Chin region and took the same route as Schlagintweit had done earlier.

[20] In 1870, a trade mission was sent to Yarkand under the leadership of T. D. Forsyth, during which all the routes through Aksai Chin were explored.

[23] During the Sino-Indian War in 1962, Tanshuihai region served as the main communication artery for 3 fronts of the Chinese offensive.