As the sun slowly slid down behind towering peaks, unseen birds sang to each other in the lush orange groves lining the cliffs – the only sound except for the soporific hum of my riverboat. The bushy green landscape was broken now and then by precipitous, rocky cliff faces dotted with a solitary house here, a death-defying road there.

In the fading light my eyes met those of a local farmer, wicker basket on his shoulders, balanced on the back-breakingly steep slope. After a brief glance he went back to tending his orange bushes, indifferent to the eyes trained on him as our boat glided past his back garden. In a land that's changing at such a breakneck pace it's these glimpses of traditional lifestyles – unchanged for hundreds of years – that truly capture the imagination.

Gorge followed spectacular gorge as we surged upriver. But there was no danger of suffering from gorge fatigue; after all, this is China, where everything – from cataracts to kitchens – is connected with its own myth, legend or superstition.

Welcome to the Yangtze River, the third-longest waterway in the world and the lifeblood of China, where it's known simply as the Chiang Jiang – 'Long River'. One-third of the country's 1.3 billion people live along its 6,211km course; 70% of China's rice is grown here; it provides 40% of the country's water. But more than that, for locals it's the main highway, always open even when winter snows block land routes. "This river is like the roads in Shanghai – so don't be surprised if you enjoy a 'horn moment'," cruise manager Max warned me on my first day on board. I quickly discovered what he meant: horns blared with ear-splitting intensity as we sailed upriver. We were setting out on a four-night cruise between Maoping and the city of Chongqing, through the famous Three Gorges, past Chinese longboats, river cruise vessels, tiny junks and barges laden with coal, sand and lorries. This river is truly alive – and truly very noisy.

In between urban areas are peaceful stretches of enormous beauty – but the Yangtze's gently flowing spring waters are deceptive. Millions have died in summer floods over the past century – 2,000 people drowned in 1998 alone, just a year after the government embarked on the $26 billion Three Gorges Dam project, devised to prevent such disasters. And another 600 perished in the 2007 flood season.

Try as I might, my imagination couldn't transform that mountain into a peach.

The dam is probably the most controversial construction project in the world. More than one million people have been relocated to concrete apartments in new towns, their old houses disappearing under the rising waters. But in a country whose population and economy are booming as much as China's, this is considered a necessary evil, and for many of those relocated it's a real boon – apartments in the new towns have more living space and mod cons such as flushing toilets and hot water. Not only will the dam save lives through improved flood control, there's also a hugely important green benefit – hydro-electric power from the dam is predicted to provide 15% of China's electricity by 2009, helping reduce carbon emissions.

And while the landscapes of the Yangtze are inevitably changing as the waters rise, many attractions continue to charm. The delightfully named Summer was my guide on a visit to the equally charmingly monikered Snowy Jade Cave. So named because the rock formations are snow white – like pure jade – Snowy Jade Cave is reached by a scenic 30-minute drive alongside Dragon River and past paddy fields and old farmhouses. We climbed up three levels, past dramatic stalactite and stalagmite formations growing 33 times faster than those in caves elsewhere.

"We say our cave is like a girl. She grows faster because she is young," Summer laughed. I was struck by a formation called the 'bathing beauty' – incredibly like the back of a naked woman in the shower. And so authentic, I mused – as the water spray soaked me.

Back on board the riverboat, gorge followed spectacular gorge as we surged upriver. But there was no danger of suffering from gorge fatigue; after all, this is China, where everything – from cataracts to kitchens – is connected with its own myth, legend or superstition. "We see the first and last gorges as strong men, but this middle one is a woman – because of its gentle mountains covered with trees and grass," our river guide Owen explained as we cruised into Wu Gorge.

He pointed to a peak, the first of 12 lining this gorge. It was once a dragon that brought bad luck to the locals, but was tamed by a beautiful goddess – or so the legend goes. On Owen's advice, I held out my left hand, palm flat to the mountain, to try to locate Shennu Feng – the Goddess Peak, so-called because of the upright stone that resembles a beautiful lady.

Around the gorge rise Climbing Dragon, Assembled Crane and Flying Phoenix peaks – if you can picture them. I strained my eyes, but it proved a flight of fancy too far for me. "We have to use our imagination as we pass through this gorge," Owen admitted. I didn't need any imagination to admire the mist-covered peaks that line the gorges, soaring an average 900m above sea level, or the steps cut through the inside of the mountain, from water level to the top, created to allow people to reach nirvana.

West of Wu Gorge, a smaller boat took me through the Lesser Three Gorges, entering under the Dragon's Gate Bridge. "We call it the Bye Bye Bridge – it is being taken down next year," our tour escort whispered. Until 2003, only junks were able to navigate these smaller gorges; when the water level rises again next year bigger boats won't fit under the bridge.

It's a spectacular construction at the start of an eyecatching route: the Lesser Three Gorges are even more stunning than their big sisters. Narrow and vertiginously steep, the gorges are dotted with houses and farms that will disappear when the water level rises. Higher up the slopes, two coffins hang from the rock face, and will be more easily spotted when the waters peak. Because of its very inaccessibility, this spot was a favourite burial place some 2,000 years ago; sadly, that wasn't enough to keep it safe from later visitors. During the Cultural Revolution, Mao's Red Guards destroyed all but these two coffins. I was reminded again of China's glorious past – and how the development of modern China makes it such a fascinating, unpredictable destination.

Back on the main river, our final farewell from the Three Gorges came at Qutang Gorge, the most westerly of the big ravines. Along the sheer walls I spotted the remains of an ancient walkway, chiselled by hand from the solid rock many hundreds of years ago to enable farmers to carry goods to market during the floods, when the river was too wild for small boats. As we sailed out of the gorge, Max turned to me with some final advice. "Look back now – see the Immortality Peak? It's called that because it resembles a peach – which in China represents long life." Try as I might, my imagination couldn't transform that mountain into a peach. Even so, Immortality Peak seemed a fitting symbol of resilience, and of the ever-smiling people I had met in this fascinating land.

By Jane Archer

Jane travelled on one of viking cruises' luxury ships. Bales Worldwide offers 3, 4 night cruises between Chongquing and Yichang with prices starting at £2174 plus £121 tax for a ten night holiday, or £2474 plus £121 tax for a 16 night holiday which includes a 9 night cruise taking in the dramatic Three Gorges and the Lesser Three Gorges, rural villages and sacred mountains. You can also explore Beijing's Forbidden City and see the vast army of Terracotta Warriors. Call 0845 057 0600 or visit www.balesworldwide.com  for more information. Information correct at time of going to press