SHIMLA
UNESCO World Heritage line since 2008, running since 1903, with 100+ tunnels. Book through IRCTC when reservations open 60 days ahead - peak services (April-June, holidays) sell out within minutes. The Shivalik Deluxe Express is fastest and most comfortable; premium and glass-roofed coaches have the best views. Short runs (Shimla to Summer Hill or Taradevi and back) work if you can't get a full Kalka seat.
The 96-km narrow-gauge Kalka-Shimla Railway was built between 1898 and 1903 under engineer Herbert Septimus Harington to connect the summer capital to the plains rail network, opening on 9 November 1903 and dedicated by Viceroy Lord Curzon. The line traverses 102 active tunnels, 969 bridges, and 912 curves, including the world's longest tunnel at the time (Barog) and the multi-arch Kanoh viaduct, remarkable feats of colonial-era engineering on a steep 1:33 gradient. UNESCO inscribed it as a World Heritage Site on 8 July 2008 under the Mountain Railways of India designation.
