Maria Guagnin et al/The Conversation About 12,000 years ago, high up on a cliff in the desert of northern Arabia, an artist (or perhaps artists) was hard at work. Standing on a narrow ledge and with primitive tools, they engraved into the rock an image of a life-sized camel. This wasn’t the first artwork of its kind: in fact, there was already an entire row of fresh camel engravings on the 128 foot high (39 meter) cliff face, below which a shallow lake sparkled in the sunshine. Over thousands of years, these engravings weathered the elements. They gradually eroded until they were almost invisible and had been forgotten. That is, until our international team discovered them and more than 170
