This 5,500-year-old monument, recently uncovered about 206 miles northwest of Lima, Peru, is part of what could be the oldest settlement in the Americas. The circular space, built of stones and adobe, was probably a social and religious gathering area, says German archaeologist Peter Fuchs, who led the dig’s excavation team. This find and others nearby (including the ancient city of Caral and a 3,600-year-old adobe carving of a human sacrifice) are rewriting history by showing that the Americas had booming civilizations at the same time that Mesopotamia was thriving half a world away.