The Karakoram Highway saves its biggest flourish for the end. From Sost, the last Pakistani town, the road climbs nearly 1,900 vertical metres through a sequence of widening valleys to the Khunjerab Pass — at 4,693 m the highest paved international border crossing in the world, where a monumental gate marks the line between Pakistan and China. Snow peaks rim a broad grassy saddle, prayer-flag-bright tourist buses idle in the thin air, and you can walk up and touch the border itself.
The drive is a safari in its own right. The pass sits inside Khunjerab National Park, established in 1975, and wildlife sightings are routine: ibex posing on roadside crags, herds of blue sheep (bharal) on the slopes, golden marmots whistling from the turf, and shaggy yaks grazing the high pastures. The park is also core habitat for the snow leopard — rarely seen, but genuinely here, which gives the empty upper valleys an electric quality.
At the top, novelty stacks on novelty: the world's highest ATM (a working National Bank of Pakistan machine), the border gate photo, Chinese watchtowers across the line, and the simple thrill of standing at almost 4,700 m having driven the whole way on smooth tarmac. It is properly high — walk slowly, drink water, and expect a pounding heart on the gate steps.
Khunjerab is a long but classic day trip from Karimabad: roughly 4–5 hours each way with stops, passing Attabad Lake, Gulmit, the Passu Cones and Sost, where passports are checked at the immigration post even if you're not crossing. The pass is open to tourists roughly April–November; snow closes the road in winter. For what the upper highway is like in the off-season, read A Winter Drive to the China Border. Go early, carry your passport, and keep the afternoon free for slow photo stops on the way down.
