English: The Darjeeling Himalayan Railway, also known as the Toy Train, is a 2 ft narrow-gauge railway based on zig zag and loop-line technology.It was declared a World Heritage Site by UNESCO in 1999.All the steam locomotives currently in use on the railway are B-Class, built by Sharp, Stewart and Company and later the North British Locomotive Company between 1889 and 1925. A total of 34 were built, but by 2005 only 12 were still in use or being repaired by the railway.Four diesel locomotives are in use: Nos. 601–2, 604 and 605 of the NDM6 class, transferred from the Matheran Hill Railway.