Ancient mounds in America

In the middle of Louisiana State University’s campus stand two earthen mounds, each c.5.5m tall. The LSU Campus Mounds have long been known to be among the c.800 mounds created by ancient indigenous communities in this region, but archaeological investigations recently published in the American Journal of Science (https://doi.org/10.2475/06.2022.02) have shed new light on the history of their construction, and revealed that one of them may be the earliest known man-made structure in the Americas still standing today. By collecting and dating sediment cores from both mounds, researchers were able to discover that construction first began on the southern mound (Mound B) as early as c.11,000