The rock art of the Australian Aborigines represents the longest continuously practiced series of artistic traditions anywhere in the world. The site of Ubirr in Arnhem Land, northern Australia, contains one of the most impressive assemblages of Aboriginal rock painting, ranging from the earliest periods to works created within living memory. A favored camping place during the annual wet season, the rock faces at Ubirr have been painted and repainted for millennia. The sequence of rock art at Ubirr and other sites in Arnhem Land has been divided into three periods: Pre-Estuarine (ca. 40,000?6000 B.C.), Estuarine (ca. 6000 B.C.500 A.D.), and Fresh Water (ca. 500 A.D.present). These classifications are based on the changing style and iconography of the images.
Pre-Estuarine rock art is characterized by a variety of images in red ocher pigments. In historic times, such images were created with brushes made from bark, feathers, or the chewed ends of sticks, and it is likely similar tools were used in the past. Among the most distinctive images are the animated stick figures of the Dynamic Figure tradition, which are often depicted clad in elaborate regalia and shown participating in hunting and other activities. Some contemporary Aboriginals identify these figures as mimi, slender spirits who taught humans to hunt and paint during the Dreaming, or creation period. In present-day Aboriginal belief, many Dynamic Figure images are said to have been painted by mimi rather than humans. Pre-Estuarine rock paintings also include depictions of extinct animals and enigmatic beings that combine the features of humans and wild yams.
Rock painting had several functions in historic times. Images were created to increase the population of game animals or for use in magic. Depictions of important Dreaming beings are common, as well as secular paintings made for amusement. Although the original significance of Ubirr's prehistoric images is unknown, they likely had similar functions.