The settlement at Darjeeling really began in 1828 with British interest. By 1835, it was separated from Sikkim for establishing a Sanatorium for the invalid servants of the East India Company. It then consisted of a monastery on observatory hill clustered with about 20 huts and a population of about 100 people. Planning began in 1839, to lay out the Darjeeling Town and construct a hill road connecting Siliguri, Pankhabari, Kurseong and Darjeeling. At the same time, evolution of hotels began, the first being The Darjeeling Family Hotel?s, followed by other hotels. By 1840, Darjeeling Town had about 30 buildings and a few respectable houses. Mother Teresa was involved in the first convent school, established in 1846. Tea bushes were brought in by the British from China and Tea plantations began spreading rapidly from 1857. To meet the expanding requirements, a new road fit for carts was planned in 1861. Subsequently, in 1879, the Darjeeling Himalayan Railway was constructed on the same hill cart road.It is recognized as a WORLD HERITAGE SITE.

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http://dhr.indianrailways.gov.in/

Suggested Reading for travelers to Darjeeling