The Mayas were never a "true" urban culture; the urban centers were almost entirely used as religious centers for the rural population surrounding them. Therefore, the decline of the urban centers after 900 AD did not involve titanic social change so much as religious change; it is believed by some scholars that the abandonment of the cities was primarily due to religious proselytizing from the north. Nevertheless, the Classic period saw an explosion of cultural creativity all throughout the region populated by the tribes we call "Mayan." They derived many cultural forms from the north, but also devised many cultural innovations that profoundly influenced all subsequent cultures throughout Mesoamerica. Much of Maya culture, particularly the religious reckoning of time, is still a vital aspect of Native American life in Guatemala and Honduras.
Mayan religion was characterized by the worship of nature gods (especially the gods of sun, rain and corn), a priestly class, the importance of astronomy and astrology, rituals of human sacrifice, and the building of elaborate pyramidical temples.
The Maya is a Mesoamerican civilization , noted for the only known fully developed written language of the pre-Columbian Americas, as well as its art , architecture , and mathematical and astronomical systems.
The Maya calendar uses three different dating systems in parallel, the Long Count , the Tzolkin (divine calendar), and the Haab (civil calendar). Of these, only the Haab has a direct relationship to the length of the year.