Circular plaza (IMAGE) University of Wyoming Caption A team including University of Wyoming anthropologists works at the site of a circular plaza that was built around 4,750 years ago in the Cajamarca Basin of northern Peru Credit Jason Toohey Usage Restrictions None 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.