Image by Tim Makins Getty Images
The Darjeeling Himalayan Railway, known affectionately as the toy train, made its first journey along its precipice-topping, 2ft-wide tracks in 1881 and is one of the few hill railways still operating in India. It has had Unesco World Heritage listing since 1999. Two-hour 'joy rides' just from Darjeeling to Ghum and back satisfy most people's toy train urges. There are normally around six of these pulled by antique steam locomotives daily, and three or so with diesel engines.
Just one (diesel-powered) train in each direction daily makes the whole 88km (seven-hour!) trip between New Jalpaiguri and Darjeeling; another runs just from Kurseong to Darjeeling and back.