Khunjerab is the top of the road, and the road, in this case, is the Karakoram Highway. At 4,693 metres, the pass sits on the border between Pakistan and China and is the highest paved international crossing in the world. There is not much to see except a white arch, a barrier, a few border markers and an enormous sense of space. The surrounding hills are high, bare and rounded, covered in snow for most of the year, and the sky seems closer than anywhere else. The name itself comes from local words meaning something like the valley of blood, though the story behind it is disputed.
The pass is open to traffic only for part of the year, usually from the spring until late autumn, when snow blocks it. Even in July, the temperature can drop below freezing at night, and the wind is cold and constant. Altitude is a real problem. Riders arriving quickly from lower levels may feel headaches, breathlessness and nausea, and a carburetted bike will run noticeably rough in the thin air. Take it slowly, drink a lot, and do not stay too long at the top if you feel unwell.
The area is protected as the Khunjerab National Park, one of the highest in the world, home to Marco Polo sheep, with their huge spiralling horns, as well as ibex, blue sheep, snow leopards and Himalayan marmots. Yaks graze the high pastures in summer, and on the road up you can see herders' stone huts. The long ride from Sost, the last Pakistani town and customs post, takes you through a stark, glaciated landscape, past peaks over six thousand metres and frozen streams.
Crossing into China is not possible for an independent rider without a lot of arrangement, usually requiring permits, a guide and specific paperwork, so for most, the pass is the end of the road. Sost has fuel, simple food and the immigration office, and you should fill up there. There is nothing at the top beyond a checkpoint and, occasionally, a small tea stall. Pack warm clothes, as the descent is long and chilly, and expect the road to be rough in places after the winter, with potholes and washed-out sections.