The island’s mountainous interior is a mystical, religiously significant region filled with tea trees, train tracks and possibly Buddha’s tooth.

The train toward Sri Lanka’s towering Sri Pada mountain moved slowly, spiralling up inch-by-inch through steep ravines lined on either side by lush green seas of tea leaves. In between the tightly packed rows of trees, women clad in bright saris stooped to pick the tea at a furious pace, ripping off handfuls of green with remarkable speed, leaving each branch completely bare before moving on to the next. As the train climbed higher, their profiles gradually faded into blurry silhouettes on the landscape. As a slight rain started to fall, each woman opened a wide umbrella, a rainbow of polka dots popping up amid the ocean of green.

Sri Lanka has been a travel hotspot ever since its 25-year civil war reached a definitive end in 2009, with tourism numbers growing by 33% in 2011. In a stark contrast to the white sand beaches most often associated with the Asian island, the country’s “hill country” is an emerald, mist-enshrouded region, dominated by mountains older than the Himalayas and connected by an enduring train system, built in the 1860s by British colonialists. After two decades of war-related bombings that scared even many locals off train travel here, the end of the conflict has made the railways an attractive option again. Today, first-class observation cars with panoramic windows let leaf-peeping tourists zoom through the hill country in one day. Alternatively, you can ride alongside Sri Lankan families in the slower-moving second- and third-class trains, getting off each day to explore a slice of the region on foot.

The gateway to the hill country is Kandy, the capital of an ancient Sri Lankan kingdom that, thanks to its strategic elevated position, held off 16th-century European invaders for several hundred years longer than the rest of the island. To this day, Kandy remains the centre of Buddhist spiritualism in Sri Lanka. Clustered around a serene lake, the city is framed by two striking religious monuments — a towering white Buddha that looks down on the city from the hills and the gold canopied roof that crowns the lakeside Temple of the Tooth.

According to legend, the temple contains one of Buddha’s teeth, retrieved from the funeral pyre in India where he was cremated some 2,400 years ago, sometime in the 5th Century BC. Today, all Sri Lankan Buddhists (70% of the population) believe they must visit Kandy at least once to pay homage to the Enlightened One’s long-decaying cuspid. Inside the shrine, hundreds of worshipers pray quietly below sweeping ceiling murals that depict historical Buddhist scenes, working their way toward the gold casket said to hold Buddha’s tooth. Anyone can visit the temple and walk through, but only devotees are allowed past the heavy gilded door guarding the room where the tooth is held.

Fifty kilometres along the train route from Kandy lies the path to Sri Pada, a holy shrine of a much different nature. Ancient Sri Lankans are said to have found the 2,200m-mountain topped by a giant footprint, and thus, Sri Pada holds religious significance for each of the island’s religious groups. Hindus believe it is where Lord Shiva first set foot on Earth; Buddhists claim it as the oversize mark of their lord; and some Muslims and Christians worship it as the spot where Adam stood in penance after being expelled from Heaven.

During the December to May pilgrimage season, hundreds of Buddhists gather at the mountain’s base each morning, starting the climb a 3 am or earlier to avoid the daytime heat and reaching the summit in time to see the sunrise. They range from grandfathers with traditional flowing sarongs hanging over their bare feet to teenagers clad in polo shirts and trainers, all climbing the 5,000-odd stone steps that are illuminated by electric lights throughout the night, a glowing white line spiralling up the mountain and marking the way to the top. Upon reaching the summit, each pilgrim rings a bell paced there, one chime for every climb they have completed in their lifetime, then they jostle for a position along the summit’s edge to watch the coming sunrise.

In contrast to that mass of humanity, the hill country’s third great site, Horton Plains, is a secluded national park set on a curving plateau 25km from Ohiya, a spit-size village adjacent to the train tracks, where any of the guesthouses will arrange transportation to the park. There, thick emerald forests give way to wild grasslands reminiscent of the African savannah. At a spot known as World’s End, the plain suddenly drops off altogether and the view opens up through the mountains, stretching down 900m  to the verdant tea plantations below, on clear days even revealing a sliver of the Indian Ocean 160km away — each geographical element of this remarkably diverse island suddenly lined up together.

Yet for all of the natural beauty of the hill country, its most memorable aspect may well be the journey itself. Waiting alongside the train tracks as the perennially late locomotive rumbles into hearing distance long before it arrives. Sitting on the edge of an overcrowded train car, feet dangling over the side as the green mountains take over and the picturesque coastline fades away. Grabbing lunch from salesmen who push their way through packed cars, offering hot samosas (deep fried pockets of pastry stuffed with chickpeas and vegetables) wrapped in someone’s reused geometry homework. Settling into a seat as day turns to night and twilight adds a mischievous element to the ride, with a burst of hooting and hollering breaking out each time the train passes through a darkened tunnel. When it emerges, flashes of lightening illuminate the hills and valleys — lighting up Horton Plains, the peak of Sri Pada and the never-ending tea plantations.