in the northern lowlands. Following Chichén Itzá, whose political structure collapsed during the Early Postclassic, Mayapán rose to prominence during the Middle Postclassic and dominated the north for c. 200 years. After Mayapán's fragmentation, political structure in the northern lowlands revolved around large towns or city-states, such as Oxkutzcab and Ti’ho (Mérida, Yucatán), that competed with one another. Toniná, in the Chiapas highlands, and Kaminaljuyú in the central Guatemala highlands, were important southern highland Maya centers. The latter site, Kaminaljuyú, is one of the longest occupied sites in Mesoamerica and was continuously inhabited from c. 800 BCE to around 1200 CE. Other important highland Maya groups include the K'iche' of Utatlán, the Mam in Zaculeu, the Poqomam in Mixco Viejo, and the Kaqchikel at Iximche in the Guatemalan highlands. The Pipil resided in El Salvador, while the Ch'orti' were in eastern Guatemala and northwestern Honduras. In central Mexico, the early portion of the Postclassic correlates with the rise of the Toltec and an empire based at their capital, Tula (also known as Tollan). Cholula, initially an important Early Classic center contemporaneous with Teotihuacan, maintained its political structure (it did not collapse) and continued to function as a regionally important center during the Postclassic. The latter portion of the Postclassic is generally associated with the rise of the Mexica and the Aztec Empire. One of the more commonly known cultural groups in Mesoamerica, the Aztec politically dominated nearly all of central Mexico, the Gulf Coast, Mexico's southern Pacific Coast (Chiapas and into Guatemala), Oaxaca, and Guerrero. The Tarascans (also known as the P'urhépecha) were located in Michoacán and Guerrero. With their capital at Tzintzuntzan, the Tarascan state was one of the few to actively and continuously resist Aztec domination during the Late Postclassic. Other important Postclassic cultures in Mesoamerica include the Totonac along the eastern coast (in the modern-day states of Veracruz, Puebla, and Hidalgo). The Huastec resided north of the Totonac, mainly in the modern-day states of Tamaulipas and northern Veracruz. The Mixtec and Zapotec cultures, centered at Mitla and Zaachila respectively, inhabited Oaxaca. The Postclassic ends with the arrival of the Spanish and their subsequent conquest of the Aztec between 1519 and 1521. Many other cultural groups did not acquiesce until later. For example, Maya groups in the Petén area, including the Itza at Tayasal and the Kowoj at Zacpeten, remained independent until 1697. Some Mesoamerican cultures never achieved