There is but one way to cross from China into Pakistan: the Karakoram Highway, a misnomer because it is a road so narrow and winding, at heights of up to 5,000 metres, that it resembles a mountain climbers' trail rather than an automobile thoroughfare. In a drop-top four-wheel drive, I roll through the heart of the Karakoram Range, gargantuan mountains on the Himalayas' western edge and home to K2, the world's second tallest summit. It is a stunning drive along the highest international road on Earth, marked by unbelievably sheer peaks and almost mystical towns inhabited by some of the friendliest people you could meet.
The highway begins in Kashgar, an ancient outpost of the Silk Road and the last officially Chinese city west before you fall off into the Republic of Tajikistan. But if you go south instead, you head towards the mountains of Pakistan. For two days, as our vehicle weaves up steadily winding roads, I can feel myself nearing the clouds; it feels as though I'm staring out the window of an aircraft. The mountains reach almost 8,000 metres, a height too staggering to conceive of even when you're halfway up.
The China-Pakistan border crossing - at 4,694 metres, the world's highest - lies on the Khunjerab Pass, the highest point of a highway that, after three days of driving on stones and through ditches, makes you wonder if its builders failed to understand that 'highway' means wide, multi-lane, paved road and not simply a way that is high. Thankfully, when we cross into Pakistan, we are warmly greeted by trigger-happy Pakistani soldiers, shooting not bullets but photographs of their strange-looking foreign guests. Race and ethnicity melt at such cross-roads, where people are extensions of China or southern Asia or both.
Passports aren't stamped at Pakistani immigration until after several more hours of having a driver speed your rickety vehicle around the edges of snow-capped mountains and past overturned trucks that look like abandoned graves. The stamping happens in a border town called Sost, where a few army officers make pleasant conversation with us before writing our passport details in a sort of huge accounting book. I worry whether, when we leave Pakistan in two weeks via an airport, the information from the ledger will have been relayed to a computer system in time, otherwise it will look like we are leaving a country we've never entered. As with most things in Pakistan, I'll have to wait and see.
If you stop at only one place on your way down the Karakoram Highway, let it be Karimabad, a town a few hours beyond Passu nestled on the side of a hill in the Hunza Valley. Hunza, home to the 800-year-old Baltit Fort, is one of a handful of places in the Himalayas suspected to be the Shangri-La that James Hilton described in Lost Horizon. I understand why as we stroll through its cobblestoned streets and along the water catchments that traverse the valley while snaking through terraced farms and trees bursting with fruit. Quaint, roadside shops sell intricate fabrics woven by women from the villages, and there is even a cafe where visitors can buy a western breakfast while watching four-legged traffic go by.
The views from most of the small hotels in Karimabad are enchanting, because just about every building in the town sits on a precipice and looks into the valley, which is dominated by all 7,788 metres of Mount Rakaposhi, or Mother of Mist, whose north face is, in mountaineering terminology, the highest uninterrupted mountain face in the world. At sunset, the stars begin to shower and the moon rises rapidly from behind the mountains. Legend has it that people live long lives in Hunza because the water has magical powers.