There are more than 50,000 pieces of rock art (petroglyphs) and inscriptions all along the Karakoram Highway in Gilgit-Baltistan, concentrated at ten major sites between Hunza and Shatial. The carvings were left by invaders, traders, and pilgrims who passed along the trade route, as well as by locals. The earliest date back to between 5000 and 1000 BCE, showing single animals, triangular men and hunting scenes in which the animals are larger than the hunters. These carvings were pecked into the rock with stone tools and are covered with a thick patina that proves their age.