This prehistoric rock art is one of many petroglyphs found on Signal Hill in Saguaro National Park in Tucson, Arizona. Petroglyphs are found throughout the American Southwest, wherever prehistoric people lived or journeyed. The carvings were chipped into the rock by the Hohokam peoples over 1,000 years ago.
It is unknown exactly what these carvings mean. They might have been of religious or ceremonial significance, or clan symbols, or decorative motifs. Or perhaps they are simply ancient graffiti.