<P> Three of these railways , Darjeeling Himalayan Railway , Nilgiri Mountain Railway , and Kalka -- Shimla Railway have been collectively designated as a UNESCO World Heritage Site , also named as `` Mountain Railways of India '' , while the fourth railway , Matheran Hill Railway is in tentative list of UNESCO World Heritage Site . These all are narrow - gauge railways . The Nilgiri Mountain Railway is also , the only rack railway in India . </P>
three mountain railway lines in india which has been designated as unesco world heritage site
Darjeeling Himalayan Railway Nilgiri Mountain Railway Kalka -- Shimla Railway