Set around the lush Tamgaly Gorge, amidst the vast, arid Chu-Ili mountains, is a remarkable concentration of some 5,000 petroglyphs (rock carvings) dating from the second half of the second millennium B.C.E. to the beginning of the 20th century. Distributed among 48 complexes with associated settlements and burial grounds, they are testimonies to the husbandry, social organization and rituals of pastoral peoples. Human settlements in the site are often multilayered and show occupation through the ages. A huge number of ancient tombs are also to be found including stone enclosures with boxes and cists (middle and late Bronze Age), and mounds (kurgans) of stone and earth (early Iron Age to the present). The central canyon contains the densest concentration of engravings and what are believed to be altars, suggesting that these places were used for sacrificial offerings.