Stone age cave painting of horses from Chauvet, France. The paintings there are the oldest known, carbon-dated to approximately years ago, almost twice the age of the Lascaux cave paintings. ** I really want to visit one of these caves.
This petroglyph from Siberia is dated to around 5000 BCE. (It reminds me of legends of many-headed demons from the Ramayana, though Ravana had ten heads. And also of Tilak's theory of an Arctic source for the Vedas).