Darjeeling, West Bengal, India. The famous Darjeeling Hill Country lies immediately south of Sikkim. Many Sikkim students leave Sikkim to attend college or university in Darjeeling, Siliguri, Kalimpong or even further afield in Kolkata.
Three historic railways comprise a World Heritage site recognizing their importance in trade and technological development. Still in use today, the Darjeeling Himalayan Railway, Nilgiri Mountain Railway, and Kalka Shimla Railway were all begun or completed in the 19th century.