Tamil Nadu's Nilgiri Mountain Railway is one of the world's steepest rack-and-pinion railways. The route was established over a century ago and the cogwheel-driven Blue Mountain Express is now UNESCO World Heritage listed.
Tamil Nadu's Nilgiri Mountain Railway is one of the world's steepest rack-and-pinion railways. The route was established over a century ago and the cogwheel-driven Blue Mountain Express is now UNESCO World Heritage listed.