All across the world, rock art provides a great source of information about people and civilizations long gone—sometimes the only source. In the United States, the greatest concentration of petroglyphs can be found in the Southwest, where the climate and lack of vegetation have preserved them for, in some cases, thousands of years. They can be found all over—in valleys and on mountaintops, deep within caves and right out in the open.
These sometimes mysterious works depict everything from abstract shapes and celestial bodies to animals and natural subjects. They can provide a window into ancient belief systems and everyday life. Here are eight places you can see some fine surviving examples that deepen our understanding of the region.