Darjeeling Himalayan Railway, Kurseong bazaar / Angus McDonald

A new photography book examines the lesser-known gems of India's vast railway network

The Indian subcontinent is renowned for its railways. Begun during the British Raj under the rule of Governor General Lord Dalhousie, between 1848 and 1856, the Indian rail network is today the world's third-biggest, carrying more than 20 million people between 6,800 stations every day.

Yet while headline routes such as the Konkan Railway, between Mumbai and Mangalore in the south, continue to draw attention and tourist numbers, there are more idiosyncratic lines that also merit exploration.

Three of the nation's mountain railways – the Darjeeling Himalayan, the Nilgiri Mountain, and the Kalka-Shimla – are listed as Unesco World Heritage Sites. They also feature in a new photographic book, India's Disappearing Railways, that celebrates narrow-gauge lines (despite Lord Dalhousie's best intentions for the nation to operate on one broad gauge, in true Indian style, four were constructed). Australian photo-journalist Angus McDonald, who died last year, sought to document these routes, which are starting to dwindle but so often offer a snapshot of their location.

As well as the Darjeeling Himalayan, the world's oldest mountain railway, constructed to transport tea, they include lines built to carry food to famine-hit regions (the Gwalior Light Railway) and routes that join remote hill stations with the main broad-gauge network (Matheran Light Railway).

The resulting photographs capture passengers on board the trains and at the more remote stations, as well as wildlife on and around the tracks, and the stunning landscapes that McDonald's 10 chosen lines travel through.

An exhibition of McDonald's photographs can be seen at the Royal Geographical Society in London (1-22 December and 5-9 January; rgs.org), and the historian and broadcaster, Michael Wood, will be delivering an illustrated talk, "Travels in India", on 17 December at 7pm (£20; bit.ly/travelsinindia).

Proceeds will go to The Angus McDonald Trust (angusmcdonaldtrust.org), the charity established in McDonald's memory to fund healthcare projects in rural Burma.

India's Disappearing Railways by Angus McDonald is published by Carlton Books (£30; carltonbooks.co.uk)