Tiwanaku is a Pre-Columbian archaeological site in western Bolivia, near Lake Titicaca, about 70 kilometers from La Paz, and it is one of the largest sites in South America. Surface remains currently cover around 4 square kilometers and include decorated ceramics, monumental structures, and megalithic blocks. It has been conservatively estimated that the site was inhabited by 10,000 to 20,000 people in AD 800.