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
Indigenous peoples of the Americas 15th–early 16th centuries), and are known only through oral history and through archaeological investigations. Others were contemporary with the contact and colonization period, and were documented in historical accounts of the time. A few, such as the Mayan, Olmec, Mixtec, and Nahua peoples, had their own written languages and records. However, the European colonists of the time worked to eliminate non-Christian beliefs, and burned many pre-Columbian written records. Only a few documents remained hidden and survived, leaving contemporary historians with glimpses of ancient culture and knowledge. According to both indigenous American and European accounts and documents, American civilizations before and