The 96 km. journey by train from Kalka to Shimla offers an unforgettable experience. The Kalka-Shimla railway is often termed as a scientific fiction. Covering the distance through 103 tunnels and 969 bridges, it has 919 curves ( 68 km. ), 20 railway stations and 5 level crossings on the route. This is one of the most unique railway tracks of the world. It is said that a correspondent of the Delhi Gazette had first sketched this railway line sometime in November, 1847, almost half a century before it was actually constructed. The project report prepared during 1887 also failed to commence the construction of the route. Finally, a survey of the train in 1895 paved way for signing the construction contract on June 29, 1898.
Though the work on the Kalka-Shimla route was completed on November 2, 1903 yet it was opened for the general public only on January 1, 1906. It is a living tribute to the Engineers who dared to bore 107 tunnels, of which 103 are still in use. The longest tunnel at Barog traversed in 3 minutes by the toy trains, also has an interesting story behind it. This station is named after Engineer Barog who sacrificed his life here. Just 1 km. off the station, lies a forlorn tunnel and the grave of this Engineer, who tried to construct this tunnel but failed to align both sides. The wastage of a huge amount of public money forced him to embrace death. Had the tunnel been aligned properly, it would have been the longest railway tunnel in the world and would have not been running through Solan and Salogra. Besides the Barog Tunnel, other three big tunnels on this route are Koti ( 2,276 feet ), Taradevi ( 1,615 feet ) and Tunnel no. 103 ( 1,135 feet ).