The fly-drive option is not an unusual choice of holiday but, in China, it seemed more of an adventure. Renting a car in China requires a Chinese driver's licence, which I had from having lived in Beijing. It did not seem to matter that I would be travelling from Hong Kong on a tourist visa when we booked a compact SUV with Avis in Chengdu, for about 2,000 yuan (HK$2,360) a week. The booking didn't even require credit-card information and when we called the rental office a week before arrival we were told we were expected. So far, so good.

WHEN WE ARRIVE at Chengdu airport, we look in vain for car rental signs and staff at the information booth don't know where the Avis office is - but we do have a number to call. The office turns out to be 10 minutes' drive away, in a logistics zone, but the friendly staff are happy to pick us up.

The rental contract and insurance policy are in English, fortunately, and we even get the model shown on the website. The staff are worried about our itinerary, though. Chengdu has traffic restrictions based on licence-plate numbers and our car is not allowed to be driven in the city on Wednesdays, which is no problem, as we plan to be far away by then.

With one eye on the Baidu Maps app on my wife's smartphone, we head towards Kham, a historical region that covers the eastern part of the Tibet autonomous region and extends into Sichuan province. Our goal is the monastery town of Tagong, about 500km from Chengdu and 3,700 metres above sea level. Our children - Maya, 10, Eveline, eight, and Ilias, five - have been promised snow, yaks and horse riding.

The road to Kangding - at 2,600 metres, the gateway to Tibet - climbs through villages and past roadside stalls piled high with oranges, following a river punctuated with hydroelectric dams. Soon we see snow, on the mountains around Gongga Shan.

On a quiet hillside overlooking the city is Kangding's first "wholly owned foreign enterprise", the Zhilam Hostel, run by an American family. We check in and head to the cosy restaurant to feast on our first butter tea and momo (Tibetan dumplings).

A 10-minute walk down the steep road from the hostel is the Anjue Temple, a small, 17th-century Tibetan building that is an oasis of peace in a city that has not escaped Chinese-style development; construction is everywhere.

In the evening, colourful Tibetan dancers descend on Kangding's central square. More than 100 people - men in cowboy hats, old ladies with long braids and hairpieces - dance in a circle, coordinating their moves. The challenge is to work out who is leading; after watching for a few minutes, we figure out it is a modest young man, one of the few not wearing traditional clothing.

Back at the Zhilam - which means "the path of peace" - the children are excited to be lying beneath electric blankets, but it's difficult to sleep at this altitude.

After a breakfast of pancakes and milkshakes, we continue our journey, and only a few minutes out of Kangding spot our first yak, grazing a few metres from the busy road. This is the G318, one of the major highways into Tibet, and trucks laden with goods crawl up, while empty ones come down fast.

After an hour or two, we reach a pass with a white stupa surrounded by snow. At 4,298 metres, the children have their first snowball fight, but the thin air soon leaves them breathless and suffering from headaches.

We have climbed onto "the roof of the world", the Tibetan plateau, and the broad valley here is dotted with traditional houses built with dark stones and wooden beams, windows bordered with white paint.

The tarmac is flat and straight, and the views are magnificent; ideal for a road trip. Even on the smaller S215, though, I notice the occasional traffic camera, but they seem to blink for all cars, so, even though we're about 400km east of the border between Sichuan and Tibet proper, they may be for surveillance rather than speed control.

We celebrate our arrival in Tagong with what must be the best schnitzel in Tibet, at the Khampa Cafe, on a sunny terrace overlooking the town's famous monastery.

Tagong is surrounded by gentle valleys and grasslands, making it an excellent base from which to experience yak herding. Through her website, Definitely Nomadic, we have arranged to stay with Angela Lankford, an American who has been living in the area for many years and is building an ecolodge outside Tagong. She meets us in town and we follow her motorbike home.

Our first night at 3,800 metres is difficult, but we have a two-day horse-ride to look forward to.

The next day, astride our steeds and accompanied by a pair of guides, we make a steep ascent to a plateau and are rewarded with spectacular views of snowcapped mountain ranges.

We stop at a farmhouse for a lunch of tea with fried bread and yak meat, watched by the farmer's entire family. We begin to wish we'd packed a few energy bars, or any food that does not smell of yak.

Home for the night is the farm of one of the guides, a 34-year-old woman who speaks some English and has an iPhone, which is favoured in these parts, apparently, because Android devices do not support the Tibetan alphabet. As we relax, we watch her going about her chores: feeding the horses, taking care of her children, bringing in the 50 yaks herded by her seven-year-old son and, finally, cooking dinner for her hungry guests.

Everything takes place to the soft sound of monks chanting. We can't locate the prayer machine - it must be on a shelf against a windowless wall that holds the family pictures and religious objects - but we assume it will be switched off at bedtime. It isn't, and although everyone else sleeps through the night, Eveline will claim in the morning that the sound kept her awake.

Next we head for Danba, the only part of Tibet that lies below 2,000 metres. We encounter little traffic as the landscape changes from open plateau to deep narrow valleys. The village houses we pass are still Tibetan in style, but each flies the PRC flag.

Jiaju is known as China's "most beautiful village", which means it has been "blessed" with a brand new road to bring the masses to what is, in truth, little more than a cluster of houses. The beauty lies in its spectacular views.

In Jiaju, we check into a magnificent traditional guesthouse full of colourful furniture, excited about having a hot shower. Our Tibetan hosts provide a dinner of rice and vegetables and Wi-Fi, both welcome after three days on the grasslands.

To get back to Chengdu we must cross a region that was hit hard by the 2008 earthquake, and many roads are still under repair or are being upgraded. Our hosts recommended the northern road, passing Mount Siguniang, which takes us again into the snow, over a pass at nearly 4,500 metres, the highest point of our journey. On the other side, thick mist robs us of a view as we head into the bamboo forests of Sichuan.

Wolong looks deserted as it waits for its pandas to return after the earthquake (the Wolong National Nature Reserve panda park has since reopened, and the 90-yuan entry fee has been waived for Hongkongers, in recognition of the funds the city donated towards restoration). We check into a large, eerily quiet hotel where we learn the route east will be closed from 7am. So, the next morning, we make an early start on a road that proves to be the worst of our journey, in the rain and the dark, through scary long tunnels with no lighting.

After a few hours we reach Dujiangyan, and the Panda Valley research centre, where a dozen animals ignore us as they devour bamboo.

We realise how dirty the car has become when we arrive back in Chengdu, and the parking system fails to read our licence plate. The car-rental employees do not seem to mind and, before we have even boarded the plane back to Hong Kong, we are planning our next China road trip.