190 cities: The Americas in effect, formed a bridge between Classic Teotihuacán and Postclassic Tula Its peak population was around 20,000 Following the fall of Teotihuacán, Tula, also called Tollan of the Toltecs, became the dominant city Tula followed a traditional courtyard model spread over a large area Its main square reveals a transition between the monumental linear center at Teotihuacán and the clustered center favored by the Aztec The main square was a space of some 400 feet on each side, bordered to the north by several palace-type structures and a colonnaded hall and to the east by a stepped pyramid; the western and southern sides were open Tula was occupied from about 800 to 1150, at which point it was sacked and burned Its peak population is estimated to have been between 30,000 and 60,000 The Aztec looted much of Tula’s undestroyed artwork, in a sense claiming the site as an ancestor city in order to establish their legitimacy as an empire Toltec influence was felt widely, and in due time Toltec architecture and art styles were transferred to the Yucatán, especially the site of Chichén Itzá The climax of Mesoamerican urbanism came at Tenochtitlán, the great city of the Aztec empire, which rose over a period of less than 200 years from a swampy backwater island in the middle of Lake Texcoco to a vibrant, organized, complex metropolis with as many as 200,000 residents, larger than anything the Spanish knew when they arrived in 1521 In the following decades the Aztec reclaimed swampland by constructing agricultural plots called chinampas; built an immense dike system; and, through a combination of political alliances and military prowess, increased their influence such that by 1428, under the ruler Itzcóatl, the Aztec were the dominant power in the Basin of Mexico From this point they began to spread their influence throughout central Mexico As the Aztec state expanded, the capital at Tenochtitlán grew, relying on tribute from conquered territory to support a large population invested primarily in governmental, religious, cultural, and military pursuits The absolute center of activity, so to speak, was the Templo Mayor, also called the Great Pyramid, the main religious temple-pyramid The basic plan of Tenochtitlán was cruciform, with the two axes meeting at the Templo Mayor, subdividing the city into four districts, each with its own temples, squares, markets, schools, and general constructions Three causeways connected the island to the mainland, extending to the west, north, and south along the axes dividing the city The urban conceptions of the Maya were totally distinct from contemporaneous urban developments in central Mexico In Mayan settlements clear differentiation is made between three typical sectors contributing to the overall texture of the settlement The first typical sector is the central complex, featuring a group of plazas, courtyards, and plat- forms surrounded by stepped pyramids, palaces, and other constructions with ceremonial or perhaps residential functions The second area is an intermediate sector that shows declining numbers of built structures as it transitions to the third sector, the agricultural countryside Scholars not completely agree regarding site typology—whether Mayan settlements are cities by either function or demography—but the Mayan treatment of urban space was certainly unique One factor that made Mayan centers unique was the aesthetic sensibility displayed in the combination of public space, ceremonial architecture, and topographical exploitation into a functional and beautiful unity Although their techniques were limited and they were working with only a few architectural forms and urban elements—such as paved streets, reservoirs of water, platforms, low walls or embankments, stairways of various sizes, stelae, and the stepped pyramid-temples, which were crowned by roof combs and often painted a vibrant red—the Maya were nonetheless able to sculpt transformative architectural spaces Late Classic Period (ca 650–ca 900) ceremonial centers such as Tikal, Copán, Palenque, Piedras Negras, Yaxchilán, and Uaxactún were as much works of art as functional spaces By and large the Maya avoided the axial monumentality and the linear progression of the grid of Teotihuacán, favoring instead elemental surprises that give the feeling of improvisation within well-defined structures Mayan population statistics vary by site; for instance, a proposed upper limit at Tikal ranges between 40,000 and 80,000, while a suggested population for Copán is 20,000 By the ninth and 10th centuries Classic Maya civilization in modern Guatemala, Honduras, Belize, and highland Mexico was collapsing, for unknown reasons, with power shifting to the northern Yucatán lowlands Toltec influence was very important in the cultural development of the Yucatán Maya; arriving from central Mexico, the Toltec forced upon the Maya the cult of Quetzalcoatl, the feathered serpent god, and also introduced changes in local sculpture, architecture, and urban planning Chichén Itzá was a regional capital and remained an important religious center for more than two centuries South American Urbanism In South America a golden age of urbanism began in the Andes around 1000 c.e following the decline of Tiwanakan influence, as led by the rise of the Wari Empire in central Peru and of the Chimú in northern Peru and culminating with the rise of the Inca Empire in the 15th century; the Spanish arrived in 1532 The cities of the Wari empire (750–1000), including the capital of Huari and the regional center of Pikillacta, developed in opposition to each other from a planning perspective