The Chumbi Valley, called Dromo or Tromo in Tibetan,is a valley in the Himalayas that projects southwards from the Tibetan plateau, intervening between Sikkim and Bhutan. It is coextensive with the administrative unit Yadong County in the Tibet Autonomous Region of China. The Chumbi Valley is connected to Sikkim to the southwest via the mountain passes of Nathu La and Jelep La.