Surely these days it couldn't be that much fun getting to Kashgar? From Peking you can fly there in a day. Even the Karakoram Highway from Islamabad, Pakistan, built right across that same Khunjerab Pass, can be covered by bus in less than four days. If you agree with Sir Aurel Stein, who at the beginning of the century was already dismissing the trip across the pass as an "excursion for the ladies", the expedition to Kashgar might seem hardly worth the bother. Unless you really want to go to Kashgar, that is.
The fact that buses now ride over the pass does not however mean that the journey is entirely safe or adventure-free. The road, still the only land-route allowing public transport from China to the Indian subcontinent, suffers frequent earthquakes and landslides and is closed from November to May each year. Even when the road is open, falling rocks pose a constant danger. A soft option? I decided to try it for myself.
The first day, boarding the bus at Rawalpindi in the plains of the northern Punjab, I felt so horrifically hot at 8am that it was quite impossible to believe I was going somewhere cold. Even after we had started climbing into grassy hills, my clothes continued to engage in nuclear fusion with the plastic seat.
At first brilliant green, then progressively more barren, the scenery gradually contorted itself into the hot, gloomy Indus gorge, where we spent the entire afternoon suspended halfway up cliff-faces with the black river below and boulders menacing from above. Meandering on and on up the gorge towards Gilgit, we drove late into the night.
By the time I awoke in Gilgit the next morning, the heat of the plains had dissipated into a cool drizzle. I found myself drinking apricot milkshakes for breakfast in the company of Japanese backpackers. Mountains loomed through low mists. Horizontally, I was already halfway to Kashgar - but vertically I was barely one third of the way up to the Khunjerab Pass.
The next (vertical) 4,900ft (1,500m) required a second bus-journey through the Hunza valley to the Pakistani frontier-post at Sust. I sat with cheerful Punjabi traders riding to China. The way was lined by pot-bellied scree slopes, wobbling thousands of metres up into the clouds. Down below, grey expanses were interspersed with fertile terraces, wet fields and orchards, reminders of civilisation under the wildernesses above.
The bus filled with mustachioed men smelling of wood-smoke and wearing flat felt hats. Nobody spoke anybody else's language. Locked in by mountains, the area of Hunza has become a veritable Tower of Babel, a confusion of Wakhi, Barushaski, Shina and other ancient tongues. But these mountain people weren't going to China, they were just hopping on and off for short rides up the valley; when I arrived at Sust, the bus had emptied to a sinister extent. At over 9,800ft (3,000m), this was the end of Pakistan, the end of the subcontinent: dark, swept by freezing wet winds, a place to bunker by the hurricane-lamp and play cards with American college kids.
The next morning everything went to pot. At Pakistani emigration on the edge of town, I joined the American backpackers mingling with Chinese Muslims returning from Mecca. Under pelting rain and ominous black skies we queued up to be stamped out of Pakistan.
The scenery along the road up to the pass was like a vision of Hell. We crept under threatening cliff-faces. Shattered rock shut out the sky and stretched up to leering peaks. It was inevitable. The rain had rendered the road unsafe. Our driver kept having to slam on the brakes to avoid sliding rocks. The time had come for all of us to reflect on the fact that Khunjerab means "River of Blood".
After an hour we were practically falling off the cliff in our driver's increasingly desperate attempts to get the bus past fallen rocks. Impasse was inevitable: trapped both in front and behind by piles of rock - and in constant danger of being hit by flying debris - we were about to get stuck on the Karakoram Highway.
Rescue, several hours later, involved an ignominious walk back to Sust in a blizzard. The Pakistani traders remained good-humoured. The college kids and I discussed hot showers and plates of fried noodles. The Chinese Muslims, fresh from Saudi Arabia, plodded through the snow in their sandals.
Well, at least Peter Fleming's five- month journey was beginning to look a little more credible. For the next three days we lodged in Sust, exploring the tiny villages of the valley, before setting off for a renewed assault on the River of Blood.
Second time lucky. Riding through the rocky gorge, we made it this time to the top of the pass, where we entered a newer, brighter world. A frozen white river ran through a valley nudged by glaciers; pastureland appeared through melting ice. In silence we crossed the highest point, marked by a stone decorated with a red star. We had entered the People's Republic of China.
We inched into a vast bright plain grazed by yaks and camels and rimmed by mountains. Drowsy from altitude sickness, I seemed to be floating above the mountains. The first Chinese checkpoint soon disturbed this dream: two wild-eyed teenage soldiers, who must have done something very bad to get posted here, entered the bus counting heads. They stood awhile smoking, further depleting the oxygen in the bus.
And then it was on to the next night-stop at Tashkurgan. Here, the Pakistani traders suddenly appeared at Chinese customs dressed in ladies' fur coats, hats and gloves, presumably insisting that they were transvestite tourists rather than smugglers. Apart from the daily sprinkle of travellers, Tashkurgan must be the loneliest place on earth, a frozen crossing-place. At night, I found Tadjikis, Uigurs, Chinese and Pakistanis sitting in the dark, drinking and thinking of other worlds.
Another day, another bus - this time the bus to Kashgar. We spiralled down, past the fissured flanks of Mount Muztagata and along the banks of icy Lake Karakul surrounded by pale green pastureland. Further on, bare dunes of sand and gravel snaked in the wind, before our descent turned precipitous. Far away a warm, green valley came into view.
The mountains were receding behind us. In no time I felt the heat of old Chinese Turkestan. We were already passing men in skullcaps, poplar woods, donkey carts, rice plantations and mud-built houses.
Had it all been too easy then? Perhaps it had - except that our bus was about to fall apart, 24 long miles short of Kashgar. Another night on the road beckoned. Kashgar, it seemed, was still one of the world's most remote cities.
Return flights to Islamabad with Pakistan International Airlines (tel: 0171-499 5500) cost pounds 655, plus tax, until 14 June. Return flights to Islamabad with British Airways (tel: 0345 222111) cost from pounds 567 return, including tax.
Explore Worldwide (tel: 01252 760000) offers an 18-day guided tour for pounds 1,145, including return flights, transfers, transport, tent and b&b hotel accommodation, and a guide. Departing 8 May, the tour takes in Peshawar, the Khyber Pass, the Kalash Kafirs, Hunza, and the old caravan trail on the Karakoram Highway.
UK nationals must have a visa for travel to Pakistan and China. Embassy of Pakistan, 35 Lowndes Square, London SW1X 9NJ (tel: 0171-235 2044). Embassy of the People's Republic of China, 49-51 Portland Place, London W1N 3AH (tel: 0171-636 9375).