 In the community of Tepexpan, the fossilized bones more than 12,000 years old of a man were found in the 20th century.The settlement was founded in the 8th century and was an important commerce center at the time of the Spanish conquest of the Aztec Empire.After the Conquest, Acolman became the site of an important Augustinian monastery in the 16th century which still contains important art and architecture from that time period.