Take a four-hour slow train through the Eastern Ghats to discover how a remote hill station is changing the global coffee game.

Even in December, early mornings are rarely pleasant on much of India's Andhra Pradesh coast. The air is already muggy by 06:30 as a crowd mills restlessly on platform five at Visakhapatnam (Vizag) railway station. However, these would-be passengers are no ordinary commuters, but travellers gathered for an experience. When the Visakhapatnam Kirandul Passenger Special rolls onto the platform, the crowd's relief is palpable; the two vistadome coaches at the back of the train that they've been anxiously waiting to board are air-conditioned.

Indians have only a nodding acquaintance with the concept of queues, so a mad scramble ensues as the train comes to a halt. Things settle down as it chugs out of the station and gradually picks up speed. The Visakhapatnam Kirandul Passenger Special also serves as a regular commuter service headed to the town of Kirandul in Chhattisgarh state, about 400km to the north-west, and takes about 14 hours to traverse the distance. But those in the vistadome coaches are interested only in the first leg, to Araku Valley. This serene hill station is about 120km away but takes four hours as the train winds its way through a whopping 58 tunnels cut through the Eastern Ghats. The two vistadome coaches – with their extra-large windows and rotatable seats – are designed to provide panoramic views of the area's mountain peaks and valleys and its gentle forested slopes that end in rushing rivers and streams, gorges and rocky promontories.

As the train whizzes past Vizag's neighbourhoods and suburbs, it provides snapshots of a city waking up: a vegetable vendor hauling their cart, a dog walker pulled by his dog, two bleary-eyed uniformed children clutching onto their father on a scooter to school. As the city segues into wide open fields and farmlands, the images change: smoke curls lazily into the sky from a lone thatched house in the middle of a farm, a diligent farmer urges on his oxen, a tractor hauls vegetables to the nearby market. The rhythmic clickety-clack of the train's wheels is familiar and soporific.

Less than 30 minutes after leaving Vizag, the train slows considerably and begins ascending into the foothills of the Eastern Ghats. As if on cue, most seats in the coach swing to face the windows. The train climbs, plains fall away and even the sporadic habitations clinging to the peaks vanish. Hills and mountains in the distance appear blue-grey in the tender morning sun. But even before this panorama can register, complete darkness descends as the train enters the route's first tunnel. I'm startled by the sounds of adults and children screaming, in jest of course, for the few minutes it takes for us to come out the other side.

When we emerge into daylight, the sight is jaw-dropping: a series of hillocks and gentle valleys, thickly forested, stretch out to the horizon where a haze-shrouded mountain range is just a hint of the soaring peaks to come. As I try to take in as much of the scene as possible, darkness descends again, and with it, more screaming.

On the other side is another surreal and dramatic sight: tracks bent around a hill, a green wall sloping straight up on one side, and a sheer drop on the other. The train slowly chugs forward, hugging the inner curve. The vistadomes' rear position means that the entire length of the train is visible, curling against the hill as if teetering on the........

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