The Ruins of Quilmes is an archaeological site in the Calchaquí Valleys, Tucumán Province, Argentina. The site was the largest pre-Columbian settlement in the country,[1] occupying about 30 hectares.[2] The area dates back to ca 850 AD and was inhabited by the Quilmes people;[3] it is believed that about 5,000 people lived here during its heights.[2]