Dongkya or Dongkhya range, is a mountain range in the lower Himalayas that forms the eastern border of Sikkim, a state of India. Its northern tip extends to Dongkha La, and as it moves southwards, sometimes referred to as the Chola range, it is cut by Cho La, Yak La, Nathu La and Jelep La passes.
1898 Sikhim and Adjoining Territories by Laurence Waddell
1903 by William O'Connor
Nathu La(Tibetan: རྣ་ཐོས་ལ་, Wylie: Rna thos la, THL: Na tö la, Sikkimese: རྣ་ཐོས་ལ་) is a mountain pass in the Dongkya Range of the Himalayas between China's Yadong County in Tibet, and the Indian states of Sikkim. But minor touch of Bengal in South Asia. The pass, at 4,310 m (14,140 ft), connects the towns of Kalimpong and Gangtok to the villages and towns of the lower Chumbi Valley.
Image: Nathu La, a mountain pass in the Himalayas on the Indo China Border
Image: Nathula Pass Border trade road panoramio
The German expedition to Tibet crossing Nathu La.
Sikkim, Chumbi Valley, with the Nathu La pass (CIA, 1965).