The mountain pass Nathu La is located in

Nathu La is a prominent mountain pass located in the Indian state of Sikkim, situated at an altitude of approximately 4,310 meters (14,140 feet) [3]. It lies on the Indo-China border and serves as a strategic link between Sikkim and China's Tibet Autonomous Region [1]. Historically, the pass was an offshoot of the ancient Silk Road and remains one of the three official border trade posts between India and China [1]. It gained significant historical and military importance during the 1962 Sino-Indian War and the 1967 clashes [3]. After being closed for nearly 44 years, it was reopened for border trade in 2006 [1]. Geographically, it is located about 56 km east of Gangtok and is known for its alpine flora and strategic significance in the Eastern Himalayas.

Sources

1. [1] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 2: Physiography > Main Mountain Passes > p. 21
2. [2] https://bharatrannbhoomidarshan.gov.in/destinations/details/102/nathu-la
3. [3] https://indiacinehub.gov.in/location/nathu-la-pass