Along the Pakistan-China border are the world's highest mountain ranges — the Karakoram, the Hindu Kush and the Himalayas — where peaks regularly soar above 20,000 feet (6,096 meters). The highest mountain in the region is the formidable K2, which, at 28,251 feet (8,611 meters), is second in height only to Mount Everest. It is through this impossibly rugged terrain that roadbuilders blasted a road that some now call the "Eighth Wonder of the World."
The Karakoram Highway, which roughly follows the route of the legendary Silk Road, was little more than a dirt path for donkey traffic before construction began in the 1960s. Over a period of two decades, 20,000 Chinese and 15,000 Pakistani workers slowly carved their way through deep gorges and along soaring mountainsides to complete the 800-mile (1,300-kilometer) road by 1979. Topping out at 15,397 feet (4,693 meters), the road was only open four months out of the year until it was paved in the 2010s, allowing snowplows to keep it open year-round.
Despite this impressive feat of engineering, nature did not go down without a fight. Blasts and falls killed more than 800 Pakistani workers and at least 82 Chinese (although many Chinese deaths likely went unreported) [source: Kazim]. In 2010 a landslide created a massive lake that inundated 13.7 miles (22 kilometers) of the road, forcing vehicles to traverse the stretch by boat. Even with that problem now fixed, crews are constantly working to repair damage from rockslides, washouts and other issues along one of the highest paved international roads in the world [source: Ziman].