The Khunjerab Pass, at 4,733 meters (15,528 feet), is reputedly the highest metalled, border-crossing in the world. Visitors are greeted with a red sign announcing 'China, drive right', and another green sign saying 'Pakistan, drive left'. A monument declares that the highway was opened in 1982 and indulges in a bit of hyperbole by saying that the pass, is at 16,000 feet (4,875 meters). On May 1, 1986, the Khunjerab was opened to foreigners for travel between Hunza and Kashgar in Sinkiang Province. Since then, Sost has been the customs, health and immigration checkpoint on the Pakistan side and the place where people depart for or arrive from China, even though it is 54 miles from the pass.

The Khunjerab is on a continental watershed. All water on the Pakistani side flows down to the Indian Ocean, while that on the Chinese side is swallowed by the Taklamakan Desert, the name of which means, that, if you go in, you don't come out'. It is 32 kilometers (20 miles) from the top of the pass to the abandoned Chinese border post at Pirali.

The scenery is remarkably different on both sides of the pass. The Pakistani side depicts a vertical world of desert-gorges devoid of any sign of human life for about 30 kilometers (19 miles), except for the road itself. The Chinese side is a wide- open, grassy high-altitude plateau with grazing herds of yaks, sheep and goats tended by Tajik herders. Children and dogs, romp among round felt tents called Yurts. The Tajiks are a smiling and friendly lot, and the women are as happy to be photographed as the men. Camels, on this side of the border appear to be altogether different. This journey promises adventure and thrills for all enthusiasts.