A group of interrelated Native American cultures in the central and lower Mississippi valley from c. 700 to 1700 ad. Three principal new features distinguish them from the preceding Hopewell cultures. Most famous are the huge politico-religious centres of pyramidal, flat topped, earthen temple mounds, which were part of special religious practices, known as the Southern cult. They were surrounded by the wattle-and-daub houses of farmers. Inspiration for these ceremonial centres was ultimately derived from the cultures of Mexico (Mesoamerica), but exactly how is unclear. Famous sites include Cahokia (Illinois), Aztalan (Wisconsin), and Macon (Georgia), with vast mound complexes, the last two fortified. A second feature was the much decreased importance of burial mounds, and a third was the appearance of completely new pottery styles, also showing indirect Mesoamerican influence.