Colossal rock engravings may be ancient borders, study suggests

Ancient rock engravings in South America are believed to mark the boundaries of territories, according to a recent study. The engravings, found along the Orinoco River in Venezuela and Colombia, depict various designs including birds, human figures, geometric shapes, and gigantic snakes. The snakes may have a dual meaning, representing both creators and protectors in local mythology. The engravings are speculated to be between 1,000 and 2,000 years old. The researchers highlight the size and density of the engravings as remarkable, and stress the need for their preservation as tourism in the area increases.