Olmec colossal heads by Matthew Stirling in 1938 spurred the first archaeological investigations of Olmec culture. Seventeen confirmed examples are known from four sites within the Olmec heartland on the Gulf Coast of Mexico. Most colossal heads were sculpted from spherical boulders but two from San Lorenzo Tenochtitlán were re-carved from massive stone thrones. An additional monument, at Takalik Abaj in Guatemala, is a throne that may have been carved from a colossal head. This is the only known example from outside the Olmec heartland. Dating the monuments remains difficult because of the movement of many from their original contexts prior to archaeological
History of the Americas ended in 400 BC, with the defacing and destruction of San Lorenzo and La Venta, two of the major cities. It nevertheless spawned many other states, most notably the Mayan civilization, whose first cities began appearing around 700-600 BC. Olmec influences continued to appear in many later Mesoamerican civilizations. Cities of the Aztecs, Mayas, and Incas were as large and organized as the largest in the Old World, with an estimated population of 200,000 to 350,000 in Tenochtitlan, the capital of the Aztec empire. The market established in the city was said to have been the largest ever seen by