Small cog in a mythic wheel

Kate Armstrong takes a train through a region steeped in history, from Achilles to World War II.

Toot, toot! As the tiny train grinds its way along the track, a woman tending a vegetable patch straightens and waves enthusiastically to the driver. We, the 40 mainly foreign passengers on board, wave back. I'm on a unique train. It runs between the seaside village of Diakofto and the mountain resort of Kalavryta in the northern Peloponnese. The shiny blue and grey carriages, large windows and comfortable interior would send Thomas the Tank Engine into a steamy frenzy.

Four kilometres of the 23-kilometre journey are steep for a train: the gradient is 17 per cent. In these sections our lives depend on a narrow, notched girder running between the rails – a rack and pinion, or cog – that gives the carriages traction. Built by an Italian company between 1885 and 1895, the railway was a remarkable feat of engineering and, still today, with only 75 centimetres between the rails, this is the narrowest passenger gauge in the world.

In 1967, diesel engines replaced the steam ones. Finally, decades on, the entire rails, cogs, engines and carriages have been replaced. In June, after two years out of action, the train took to the tracks again. Locals and visitors alike are rejoicing – the train transports people to and from Kalavryta and is an important part of their history.

It's my lucky day. I sit with the engineer Christos Oikonomou. With his entourage of 20 workers, he was responsible for replacing the tracks. Every now and then Christos tilts his head as we pass small white cylinders on the side of the track. These are magnets, which, he explains, synchronise the train's velocity at 6km/h in steep parts. At first I think he's clearing his ears, then I realise that, as with a piano tuner, he's listening to the cadence of the track as we grind our way over it. "I know what is wrong just by the sound," he says. I've never felt so safe.

We pass a miniature model of a Greek Orthodox church, with offerings inside. My eyes widen: I assume it is a memorial commemorating a disaster. As it happens, it's a thanksgiving – the locals built it after an accident was averted. During the works and while raising one of the bridges, a carriage started to roll, potentially crushing everything in its rickety path, including the workers. Thanks to a miracle, it ground to a stop.

The train pauses briefly at the miniature station of Zahlorou, whose village's two quaint tavernas are perched right on the platform. This is the popular launching pad for hikes to the nearby cliff-hugging monastery Mega Spilaio. From Zahlorou, the train enters the stunning Vouraikos Gorge. Its steep cliffs are edged by massive boulders and plane and cypress trees, while the area is home to more than 23 species of butterflies.

The train line switches back and forth across the gorge by way of iron bridges, clinging to the narrow ledge that overhangs the cascades of water. The gorge winds and curls like a massive mythological water serpent, the train disappears into one of seven tunnels (the longest is 85 metres) and emerges again under a canopy of green and yellow.

We pull into Kalavryta's historic station, right on the doorstep of the village. The leafy, paved streets of this upmarket place are lined with tavernas, trendy bars and gourmet-style tourist shops. These days it's hard to imagine this beautiful village was the site of a massacre in World War II. On December 13, 1943, Nazi insurgents gathered the town's inhabitants. They separated the women and children from males aged over 15. The women and children were locked in the schoolhouse to be burnt to death. They escaped. The men were shot – a few survived. The clock in the tiny main square stands at 2.34pm, the time the massacre began. Elsewhere, overlooking the town stands a massive white cross and a more contemporary concrete memorial, the Martyrs' Monument.

The schoolhouse is now a museum dedicated to those killed here and elsewhere in the region. This extraordinary exhibit starts with large black-and-white photos depicting the village before the war: schoolchildren, sporting groups, village celebrations.