The Nil­giri moun­tain rail­way, a 46 km long sin­­gle-track track in Tamil Nadu, was orig­i­nal­ly expect­ed to be com­plet­ed in 1854. How­ev­er, due to the dif­fi­cul­ties of con­struc­tion in the moun­tain­ous area, work was start­ed only in 1891, and com­plet­ed in 1908. This rail­way with a height dif­fer­ence from 326m to 2203m was built in accor­dance with the high­est require­ments of the rail­way con­struc­tion of that time.