It was a monumental attempt to tame the forces of nature. For 20 years, teams of engineers blasted and bulldozed their way through the Karakoram and Pamir mountains. Hundreds of men were killed by landslides; others fell to their death in the gorges.
When the highway finally opened in 1986, there were ecstatic headlines: two nations had been united; the glorious Silk Route would again echo to the sound of traffic. Twelve years on, the road is deserted except for the occasional lorry. Cross-border wrangles and high tariffs mean that, today, most of the people who travel its 750 miles are tourists.
The Chinese stretch, from the Khunjerab Pass to Kashgar, is only 250 miles but it takes the best part of two days by public transport. From the Pakistani frontier town of Sost the road winds up through shattered mountainsides and tumbling scree before emerging at the Khunjerab Pass.
At 15,528 feet above sea-level, the pass is the highest surfaced border in the world, and a literal and metaphorical watershed. Waters on the Chinese side never make it to the ocean, disappearing instead into the sands of the Taklamakan Desert hundreds of miles away.
The jagged peaks of the Karakoram give way to a high-altitude steppeland overlooked by round-topped mountains. Farmers in black overcoats and knee-length boots ride around on camels, herding flocks of yak and sheep. You might for all the world be in Mongolia.
In fact, that is the strange thing about Xinjiang province. It is not really like China. The Han Chinese are interlopers here, trying to keep order among the indigenous Uighurs, Khazaks and Taliks. The culture is central Asian and predominantly Muslim.
Tashkurgan, the first town in Xinjiang, is only a few miles from the Tajikistan frontier. It is characterised by bizarre attempts to impose communism on the locals. Along a single tree-lined avenue, Tannoys broadcast martial music and dawn-to-dusk news reports while Tajik women cycle past in thick skirts and pillbox hats. If you are arriving from purdah-restricted Pakistan, where females are a rare sight on the streets, the appearance of women with their legs on view - even in regulation-issue lumpy brown stockings - is startling.
An air of faded melancholy hangs over Tashkurgan. There is little to see apart from a ruined fort and a handful of shops. Although Xinjiang lies 2,000 miles west of Peking, the Chinese government insists all clocks are set to Peking time - two hours behind local time.
Three hours from Tashkurgan lies Kara Kul Lake, situated at 12,000ft and with spectacular views of the snow-capped peaks of Kongur and Muztagh Ata ("Father of Ice Mountains"). Here you can pitch a tent or sleep in a yurt, one of the conical huts used by the local Kyrgyz nomads.
After Kara Kul, the highway descends through a broad plain surrounded by white sand dunes before plunging into the depths of the Ghez canyon. Colossal crags of granite and sandstone rise sheer from the roadside, depriving the canyon of all but a few hours of sunlight. The road had to be hacked out of the rock inch by inch and is prone to landslides.
The final stretch of the highway runs across flatland to Kashgar, an otherwise almost inaccessible city sandwiched between the Taklamakan Desert and the mountain ranges of Tian Shan, Pamir and Kun Lun. As recently as 1935 it took six months to reach here from Peking.
In the early part of this century Kashgar became a hot-bed of Russo- British intrigue. The modern traveller can choose between the former Russian and British consulates, now converted into brutalist hotels.
Kashgar is a pleasant place to hang out. You can wander through the bazaar with its 15th-century mosque, take a trip to the stately Muslim tombs on the outskirts of town, or sample Chinese cuisine in the night market.
On Sunday, everyone in Kashgar goes to market. Farmers with long beards and overcoats tied with drawstrings tramp through the lanes with donkeys, camels and - occasionally - their wives. Here you can buy jade from Hotan, raisins from Turfan and silk from Aksa, as well as crateloads of Maoist kitsch (cigarette lighters that play "The Red Flag" are a particular delight).
The market is a riot of sound and colour. While you wonder at the hats made from the fur of endangered species, boys dressed like urchins out of an Italian neo-realist movie pester you with ornamental knives.
Kashgar marks the end of the highway. Beyond lie 1,000 miles of desert, home to a scattering of oilmen, nuclear scientists and ruined cities half- buried by the sands.
MOST VISITORS follow the Karakoram Highway from south to north, flying in to Islamabad in Pakistan (a Heathrow-Islamabad return ticket on Pakistan International Airlines costs pounds 520 including taxes through Global Travel 0181-521 1226). From there you can fly or drive to Gilgit, the start of the most spectacular section of the highway. You will need visas for Pakistan and China.
To travel the highway from north to south, fly to Peking (see details opposite) and then take a plane to Urumxi and a bus or plane to Kashgar.
The best time to visit the Karakoram Highway is between September and October. Snow closes the Khunjerab Pass from mid November until 1 May.Reuse content