'astronomical point') is the name of a border outpost and a military defence area of China in the northern Aksai Chin region under its administration (as part of Xinjiang).

Its headquarters, the Tianwendian outpost, is in the Chip Chap River valley close to China's Line of Actual Control with India.

The name is said to have been used to describe a military defence area in northern Aksai Chin in the run-up to the 1962 Sino-Indian War.

[8] In the 1980s, a specific outpost named Tianwendian was established close to China's Line of Actual Control with India's Daulat Beg Oldi sector.

[12] Around the time of the 2013 Daulat Beg Oldi incident, PLA constructed a radar station, an 11 m radome at an elevation of 5530m, at this outpost.