India is a big country, in the way that elephants, and skyscrapers, and continents are big. To walk from the tip of the subcontinent to the edge of the Tibetan Plateau would take most of a year. To cross the country from side to side would take almost as long. Lucky then that Indian Railways is there to transport India’s 1.13 billion citizens across the vast nation they call home.

Railways in India are not just a means of transport, they are a way of life. A staggering 18 million people travel by train in India every day, on more than 9,000 scheduled services. Indeed, Indian society would be unable to function without the railways - religious pilgrimages alone account for hundreds of millions of journeys every year, and Indian Railways is the world's largest employer, with 1.6 million staff on the payroll.

The first time you travel on an Indian train will stay with you for a lifetime. Booking is an art form, involving complicated paperwork, endless queuing and a comprehensive knowledge of train numbers, station codes, and classes of travel (wise travellers invest in the invaluable Trains at a Glance, listing every service). With ticket in hand, you must then navigate the train platform, picking your way between sleeping passengers, piles of packing cases, bellowing food hawkers and over-laden porters.

But once you find your seat and the train jolts out of the station, the journey truly becomes the destination. As the loco gains momentum, chai-wallahs speed up and down the carriages with giant kettles of sweet, milky Indian tea. For overnight journeys, attendants lay out vigorously laundered sheets and deliver breakfast to your seat at sunrise. And all the while, the mesmerising landscape of India unfolds in front of your window at exaggerated speed, like an early explorer's film reel.

India is rightly famous for its classic rail journeys. Although the steam trains have mostly moved on to the great railroad yard in the sky, a few narrow-gauge steamers still chug up into the hills, following the route taken by the colonial sahibs as they fled the heat of the plains every summer. Then there are India's "palaces on wheels", the opulent former railcars of princes and maharajas, now pressed into service for the paying public.

But you do not have to shell out hundreds of dollars for the Deccan Odyssey (the no-luxury-too-indulgent service from Mumbai to Goa and Maharashtra) to feel the thrill of Indian rail travel. Even ordinary journeys from one town to the next can be extraordinary by virtue of the scenery on all sides.

Take the Konkan Railway from Mumbai to Kerala, which clatters through 92 tunnels and rumbles over 1,998 bridges as it traces the edge of the Arabian Sea en route to Cochin, affording spectacular views of palm-shaded fishing villages, broad river deltas, steamy rice padis and dense jungles.

Another epic commute - best undertaken during the June-September monsoon - swaggers through the steamy jungles of the Western Ghats between Margao in Goa and Londa Junction in Karnataka, passing within metres of the thundering Dudhsagar waterfall, the fifth highest in India.

Then there is the World Heritage-listed Darjeeling Himalayan Railway - aka the Toy Train - a narrow-gauge charmer that climbs more than 2,000m between Siliguri in West Bengal and the tea plantations of Darjeeling, completing several 360 degree loops as it strains its way through the foothills of the Himalaya.

The only disappointment is the government ban on riding on the roof of trains - once an atmospheric escape from the overcrowded and overheated 2nd-class carriages. For more information on train travel in India, visit the Indian Railways website or browse the India pages at Seat 61.

The article 'Riding the rails in India' was published in partnership with Lonely Planet.