The highway climbs over mountain passes higher than 4,600 metres above sea level. At those heights the sky is a deeper shade of blue, the air is thin and cold, and you can sometimes see for hundreds of kilometres in every direction. Yaks graze beside the road, and eagles circle above.
For most of its history the route was a track used by traders, nomads and explorers — including the famous Italian explorer Marco Polo, who travelled this way in the 1200s on his journey to China. Today trucks, jeeps and adventurous cyclists all use the road to cross the Pamirs.
Driving the full highway takes several days. There are very few petrol stations, shops or mobile phone signals along the way. Travellers need to carry enough food, water and spare tyres to look after themselves. Many people say the scenery — huge valleys, glaciers, shimmering lakes and lonely passes — makes every challenge worthwhile.