The Darjeeling Himalayan Railway nicknamed the `Toy Train` is an integral part of the picture-perfect Darjeeling town, far famed world-wide. Darjeeling Himalayan Railway is also considered as a UNESCO World Heritage Site, declared in 1999. This is the second railway to have this honour bestowed upon it, after the Semmering Railway of Austria in 1998. The railways are run by the steam engines, still in service in India. The railway connects the town Darjeeling with the plains.

The Darjeeling Himalayan Railway is a 2 ft (610 mm) narrow-gauge railway from Siliguri to Darjeeling in West Bengal, run by the Indian Railways. Darjeeling Himalayan Railway was built between 1879 and 1881 and is approximately 86 km long. The elevation level ranges about 100 m at Siliguri to about 2,200 m at Darjeeling. A standard gauge railway connected Kolkata and Siliguri in 1878. Siliguri, at the foothills of the Himalayas, was connected to the hill station - Darjeeling by a cart road or the Hill Cart Road on which "Tonga services" were available. Franklin Prestage, an agent of Eastern Bengal Railway Company appealed to the government with a proposal of putting down a steam tramway from Siliguri to Darjeeling. The proposal was accepted in 1879 and a committee was formed by Sir Ashley Eden, the Lieutenant Governor of Bengal. Construction of Darjeeling Himalayan Railway started the same year.

Gillander Arbuthnot & Co. constructed the railway and the stretch from Siliguri to Kurseong was opened on 23 August 1880, while the authorised opening of the line up to Darjeeling was done on 4 July 1881. Several engineering adjustments were made later in order to relieve the slope of the rails. In spite of natural calamities such as an earthquake in 1897 and a major cyclone in 1899, the Darjeeling Himalayan Railway continued to improve with new additional lines, and the passenger as well as goods carrying was increasing gradually. Darjeeling Himalayan Railway started to face competition from bus services that started operating along the Hill Cart Road, and took less time than the railway to reach Darjeeling. Darjeeling Himalayan Railway played a vital role transporting military personnel and supplies to the numerous camps around Ghoom and Darjeeling, during World War 2.

After the independence of India, Darjeeling Himalayan Railway was included in the management of Indian Railway, and became a part of the Northeast Frontier Railway zone in 1958. In 1962, the line was once again aligned at Siliguri and extended by nearly 4 miles (6 km) to New Jalpaiguri (NJP) to meet the new broad gauge line there. Darjeeling Himalayan Railway remained closed for 18 months during the antagonistic period of Gorkhaland Movement in 1988-1989.

New Jalpaiguri is one of the vital stations in the route of Darjeeling Himalayan Railway. The railway was extended to the south in 1964 to convene the new Broad gauge to Assam. Where the two merge, New Jalpaiguri was created. Siliguri is the original southern terminus of the line. Siliguri Junction became a major station only when a new meter-gauge line that was built to Assam in the early 1950s. The station Sukna noticeably marks the change in the landscape from the flat plains to the forested lower slopes of the mountains. Loop No.1 was in the woods above Sukna, however, it was removed after flood damage in 1991. The site is now lost in the dense forest. Rangtong is also an important station in the route of Darjeeling Himalayan Railway. A short distance above Rangtong there is a water tank that once supplied water to all the surrounding regions. Loop 2 was removed in 1942 due to flood damage, a new reverse, No.1, was added, thus creating the longest reverse run. Loop No.3 is at Chunbatti, which is presently the lowest loop of Darjeeling Himalayan Railway. Reverses No.2 and 3 lies between Chunbatti and Tindharia.

Tindharia is a major station on the line and below the station are the workshops. There is also an office for the engineers and a large locomotive shed. There are three sidings above the station and these were used to inspect the carriage while the locomotive was changed, before the train continued towards Darjeeling. Agony Point is the loop No.4. It emerges as the shape of the loop which comes to an apex which is the tightest curve on the line. Gayabari and Mahanadi are the stations on this route. There is a shed in Kurseong and a few sidings adjacent to the main line, but the proper station is a dead end. The up trains reverse out of the station and cross a busy road junction before they continue on their climb. It is said that the station was built in this pattern so that the train could enter a secure yard and stay there while the passengers left the train for refreshments. Above Kurseong station, the railway runs through the bazaar. Trains move in front of shops and market stalls on this busy expanse of road. Stations like Tung, Dilaram, Sonada, Rangbul and Jor Bungalowfall on the way. Ghoom station is the summit of the line and highest station in India. A museum is built on the first floor of the station, thus building with larger exhibits in the old goods yard. Batasia Loop falls next on the way, which is one of the striking tourist attractions of Darjeeling. The furthest reach of the line is Darjeeling Bazaar, a goods-only line and presently lost under the road surface and small buildings.

All the steam locomotives of Darjeeling Himalayan Railway currently in use on the railway are of the `B` Class, this design was built between 1889 and 1925. A total of 34 were built but by 2005 only 12 remained on the railway and in use and under repair. Locomotive number 787 has been rebuilt with oil firing. This was originally installed to work on the same principle as that used on Nilgiri Mountain Railway. To operate the oil burner and an electrically driven feed pump, a diesel-powered generator was fitted and to aid the braking system, a diesel-powered compressor was also fitted. Additionally the locomotive of Darjeeling Himalayan Railway was fitted with a feed water heater that resulted in a dramatic change in the appearance of the locomotive.

Travellers to Darjeeling have long viewed the Darjeeling Himalayan Railway with affection and enthusiasm. The trip up to Darjeeling on railway has changed little since the ages and continues to be a delight for the travelers and rail enthusiasts, so much so that it has its own protection and support group, the Darjeeling Himalayan Railway Society.

Several Bollywood movies have portrayed the Darjeeling Himalayan Railway. Especially popular was the song `Mere sapno ki rani` from the film Aradhana. Other notable films, where the Darjeeling Toy Train was shown include Jhumroo, Parineeta and Raju Ban Gaya Gentleman. The toy train coming from Siliguri is some thing, which is liked by the elders and the children equally and the real fun in coming to Darjeeling is actually on this toy train.