The mountains railways blesses the travellers with an opportunity to witness and enjoy the glorious beautiful scenes with help of bold and brave engineering work that resulted into a rail link through the mountainous region. The Mountain Railways of India, which includes three railway lines, was adorned with the tag of World Heritage Site by UNSESCO. This prominent World Heritage Site primarily includes the Darjeeling Himalayan Railway, The Nilgiri Mountains Railway and the Kalka Shimla Railway line.
The Darjeeling Himalayan Railway line is a railway line of prime importance because it was the first hill passenger railway and it opened in the year of 1881. The Nilgiri Mountain Railway line, which is a 46 km long single track line, runs in state of Tamil Nadu. Although its construction started in 1891 and finished by 1908, the proposition to build it was presented way back in the year of 1854. This delay was primarily because of the tough working situations in the mountainous regions. The Nilgiri mountain railway line is in the elevation range of 326 m to 2,203 m and when it was built it showcased the use of latest technology. The significance of the Nilgiri mountain railway was realized when it helped not only in the movement of the general population during the British era but also in the general social economic development.
The third railways line is the Kalka-Shimla Railway line and it has a total length of 96 kms. The three mountain railways are maintained to be in the best condition even today and are thus operational. The Darjeeling Himalayan Railway Line and the Kalka-Shimla Railway lines are present in the northern India in the Himalayas. However the Nilgiri mountain railway line is present in the south in the Western Ghats.
In addition to these there are four other mountain railway lines. The Kangra Valley railway (1924) and the Kashmir railway (2005), located in the Himalayan region and the Matheran Hill railway () in the Western Ghats. The last mountain railway line is the Lumding-Silchar line present in the Cachar hills of Assam. However, only the Darjeeling Himalayan railway line, the Nilgiri mountain railway line and the Kalka-Shimla railway line have been named as World Heritage Sites.