The term 'Big City' takes on a whole new meaning in China. We ended our river trip down the Yangzi River in Yichang, a small city with a mere 4 million inhabitants. We started it in Chongqing – A BIG City.

Chongqing is one of the biggest cities in the world. 40 million people live there, clinging to the mountains on the edge of the muddy Yangzi river. 40 million people grifting, eating, shitting and spitting, all in one place.

Of course it's a complete monstrosity. At once organic and mechanical, it creeps up the foothills and leeches at the river, but also steams and grinds and pounds round-the-clock like a Victorian dockyard. Walking back from dinner, we saw a JCB with a huge flashlight attached to its digger so that it could keep working through the night.

Nicknamed 'The Mountain City', its skyscrapers and concrete freeways tightly hug the contours of the terrain so that as you hike around the town, each new vista reveals another metropolis - another million homes and shops and factories and offices you never knew about, going up and falling down, construction and destruction simultaneous and indistinguishable.

And yet I found it strangely loveable. As well as the sheer awe inspired by Chongqing's scale, I felt the city had a great energy and excitement to it – and behind its ugliness, a sense of utility and lack of pretence. It's a place too busy being to worry about how it looks.

Arriving in Chongqing at the central bus station, we got a quick and dangerous taxi down to the docks to load our bags onto our cruise ship before exploring the city. Avoiding several dogged locals who wanted to carry our bags for 10 yuan (about a pound) we tiptoed over the mudflats onto the gangway and up into the belly of the boat.

'The Princess' was one of the smaller cruise ships - a three-tiered, diesel-powered ship with a dining hall and a bar and not much else. Daily shore-excursions were encouraged to avoid any Jack Nicholson-style episodes of cabin fever, but after 3 nights penned-in with 100 hardcore Chinese holiday-makers, we were starting to feel the strain.

Travelling with the locals did have its advantages though. The second night on the boat we got to experience a traditional Chinese evening entertainment – the talent show. This was kicked-off by a selection of the younger women from the crew dressing up in sexy evening wear and tottering in succession down a makeshift catwalk in the bar, to the evident delight of the older gentlemen in the audience. The 'show' then continued with several rounds of karaoke, a Chinese flute performance (think Ron Burgundy, except 5 foot tall) and a game of musical chairs which Sarah unfairly lost to a hulking young Chinese guy in a black shell-suit.

My favourite shore-excursion was a trip up a side tributary of the Yangzi. Here the gorge was much narrower, and the river became so shallow that we had to climb into little wooden bottom boats to get further upstream. From these boats we saw many new houses where farming families had been relocated after the dam was built and they found their fields underwater. We also saw a local tradition in practice – hanging coffins. This is a funeral practice of the native Bo people, where they wedge the coffins of the newly dead into cracks in the gorge walls, or balance them on wooden staves hammered into the rock face. Creepy stuff, especially as no one knows quite how they get them up there.

The wooden boats were powered by local (displaced) farmers rocking back and forth over 4 oars, or scampering along the riverbank to tow us with ropes. Apparently in the summer they work in their traditional uniforms – bamboo sandles, cotton harnesses and their birthday suits. I doubt if even this sight could have lifted Sarah's spirits however, as she spent the entire trip gripping her seat and the kind Chinese gentlemen next to her for fear of falling into the water (video to follow).

The Yangzi runs east from Qinghai province in the Northeastern part of the Tibetan plateau to the East China Sea at Shanghai. We followed the river for the most popular 600km stretch, running from Chongqing to Yichang through the famous Three Gorges: The Qutang, Wu and Xiling gorges... and then through the even more famous Three-Gorges Dam.

The gorges themselves are incredible. Some of the mountains loom one thousand metres above you, with craggy peaks tearing through the ever-present 'mist' (I'm beginning to think this 'mist' is often a euphemism for the massive amounts of smog in this country). The gorges must have been even more impressive before the dam was built – at that point the river was 30 metres lower than it was when we travelled on it, and 50 metres lower than it was last winter.

Before arriving at Yichang, we had a brief stop at the dam. I think the construction of the dam and its impact on the people living around it are much more impressive than sight of the concrete wall itself (although of course this didn't stop us taking pictures with the rest of the tourists). For example, 1.3 million people had to be relocated to build the dam, and 15 million people were 'saved' from the risk of flooding. The dam now supplies 3% of all China's electricity.

We disembarked in Yichang – the small city – and immediately headed to a nearby Korean Barbeque restaurant to enjoy some proper food after three days of buffet blandness. Thus sated we set out to explore the city, and were pleasantly surprised. The Lonely Planet is pretty scathing about Yichang, saying the only reason to be there is to get on or off of a cruise. Whilst this is true, the city still has a lot going for it. It's really relaxed, the people are friendly, local food is tasty and it's got a fantastic riverside park that stretches the entire length of the city.

Running through the park the next morning was a surreal experience. As well as the traditional tai-chi classes, we also passed a pack of 50 grannies moving in sync to a dance-version of Britney Spears, and another group of seniors doing some kind of kung-fu with real swords! My personal favourite however, which you can find in most parks in China, was the adult jungle gym. It's kind of a cross between a kids playground and an outdoor Fitness First, and its principle function appears to be to provide octogenarians with a variety of different seats in which they can lounge whilst nattering with their friends.