The Darjeeling Himalayan Railway and batasia loop

The Batasia Loop is a spiral railway created to subordinate the pitch of rise of the Darjeeling Himalayan Railway in Darjeeling district of West Bengal, India. At this point, the trace spirals around over itself through a tunnel and over a hilltop. It was commissioned in 1919.
Batasia ring is located at 27°1′0″N88°14′50″E.
It is 5 km from Darjeeling, below Ghum. here is moreover a commemorative to the Gorkha soldiers of the Indian Army who sacrificed their lives after the Indian Independence in 1947.

The Darjeeling Himalayan Railway, also known as the DHR or Toy Train, is a 2 ft (610 mm) narrow-gauge railway based on zig zag and loop line technology that runs between New Jalpaiguri and Darjeeling in the Indian state of West Bengal, India. Built between 1879 and 1881, with 6 zig zags and 5 loops, the railway is about 88 km (55 mi) long. Its elevation level varies from about 100 m (328 ft) at New Jalpaiguri to about 2,200 m (7,218 ft) at Darjeeling. Four modern diesel locomotives handle most of the scheduled services; however, the daily tourist trains from Darjeeling to Ghum (India's highest railway station), and the Red Panda from Darjeeling to Kurseong and steam enthusiast specials are handled by the vintage British-built B Class steam locomotives. The headquarters of the railway is located in Kurseong.