Göbekli Tepe calendar (IMAGE) University of Edinburgh Caption Carvings at Göbekli Tepe are thought to represent the world's oldest calendar. Credit Dr Martin Sweatman Usage Restrictions N/A License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.