The Khunjerab Pass, at 4,733 meters (15,528 feet), is reputedly the highest metalled border crossing in the world. A red sign announces 'China drive right', and a rival green sign says '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 16,000 feet (4,875 meters).

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, 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 the two sides of the pass. The Pakistani side is vertical world of desert gorges devoid of any sign of human life for the last 30 kilometers (19 miles), except for the road itself. The Chinese side is wide, open and 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 are. Even the camels are altogether different animals. Pakistani camels are tall, shorthaired, one-humped Bactrains that appear to wear hairy, knee-length shorts.