As for the northern Maya area, its cultural development took place in parallel and more or less simultaneously with that of the central area, although the original cultural stimulus came from it. Almost sharing the same cultural level, technical and scientific knowledge, and beliefs of the sister towns of the central area, the Maya of Yucatán developed different architectural styles as expected in a environment geographically different from the jungle of the central zone. In the north of the Peninsula rainfall is quite low, rivers and other surface waters are not as abundant, the mainly limestone soil with a low vegetation layer supports an even lower and sparse vegetation as it approaches the northern end of the Peninsula… In spite of this unfavorable environment, the Mayas and Yucatecos developed a very brilliant variant of the Mayan civilization as shown by the vestiges of their ceremonial centers, some as old as those of Petén (Dzibilchaltun, Cobá, Edzná). In the course of the tenth century AD, Toltec groups from central Mexico invaded the north of the peninsula and imposed their rule, mainly in Chichén-Itzá and to a lesser extent in Uxmal and other centers. The consequent fusion of constructive techniques, the imposition of new deities, the predominance of a foreign warrior caste, and the appearance of new artistic themes and styles characterized the first half of the post-Classic period (1000-1250 AD). The last centuries prior to the Spanish Conquest clearly showed the decline of this hybrid Mayan-Toltec culture, as well as the return of certain classical Mayan patterns, particularly in pottery and decoration of buildings, a phenomenon that is mainly appreciated in Mayapán and on the Caribbean coast.