Recently discovered, life-sized figures of camels carved prominently onto cliff faces in the northern region of the Arabian Peninsula were likely used to mark routes to water sources in the vast Nafud desert nearly 12,000 years ago, finds a new study involving UCL researchers. The paper, published in Nature Communications , found that these stone-age carvings indicate that humans settled in the region at a time when seasonal water sources were starting to return at the beginning of the Holocene