After the war, the region became a subdivision of the Western Duars district, and the following year it was merged with the district of Darjeeling. The temperate climate prompted the British to develop the town as an alternative hill station to Darjeeling, to escape the scorching summer heat in the plains. Kalimpong's proximity to the Nathu La and Jelep La passes (La means "pass"), offshoots of the ancient Silk Road, was an added advantage. It soon became an important trading outpost in the trade of furs, wools and food grains between India and Tibet. The increase in commerce attracted large numbers of Nepali's from the neighbouring Nepal and the lower regions of Sikkim, the areas where, Nepali's were residing since the Gorkha invasion of Sikkim in 1790. The movement of people into the area, transformed Kalimpong from a small hamlet with a few houses, to a thriving town with increased economic prosperity. Britain assigned a plot within Kalimpong to the influential Bhutanese Dorji family, through which trade and relations with Bhutan flowed. This later became Bhutan House, a Bhutanese administrative and cultural centre.