About 85 km north of Sost, the Karakoram Highway crosses into China at the Khunjerab Pass, the highest paved international border in the world. The road climbs through bare brown valleys with snow on the peaks year-round and ends at a Chinese gate hung with red banners.
Foreign visitors can drive up to the pass and back as a day trip from Sost — Pakistan immigration is checked at Sost itself, with a further checkpoint at the pass. The road is open roughly May to November, depending on snow.