Petroglyphs are rock carvings or engravings made by removing part of a rock surface to expose the underlying stone. They are usually found in areas with a high concentration of rocks, such as desert landscapes, and can be dated back thousands of years. Petroglyphs were often used by ancient cultures as a means of communication, storytelling or recording important events. The symbols and designs vary greatly depending on the culture that created them, but they are generally considered an important form of rock art.