developed urban centers. Two characteristics are most notable in Mesoamerican architecture. Firstly, the intimate connection between geography, astronomy and architecture: very often, urban centers or even single buildings are aligned to cardinal directions and/or along particular constellations. Secondly, iconography was considered integral part of architecture, with buildings often being adorned with images of religious and cultural significance. Calendrical systems Agriculturally based people historically divide the year into four seasons. These included the two solstices and the two equinoxes, which could be thought of as the four "directional pillars" that support the year. These four times of the year were, and still are, important as they indicate seasonal changes that directly impact the lives of Mesoamerican agriculturalists. The Maya closely observed and duly recorded the seasonal markers. They prepared almanacs recording past and recent solar and lunar eclipses, the phases of the moon, the periods of Venus and Mars, the movements of various other planets, and conjunctions of celestial bodies. These almanacs also made future predictions concerning celestial events. These tables are remarkably accurate, given the technology available, and indicate a significant level of knowledge among Maya astronomers. Among the many types of calendars the Maya maintained, the most important include a 260-day cycle, a 360-day cycle or 'year', a 365-day cycle or year, a lunar cycle, and a Venus cycle, which tracked the synodic period of Venus. Maya of the European contact period said that knowing the past aided in both understanding the present and predicting the future (Diego de Landa). The 260-day cycle was a calendar to govern agriculture, observe religious holidays, mark the movements of celestial bodies and memorialize public officials. The 260-day cycle was also used for divination, and (like the Catholic calendar of saints) to name newborns. The names given to the days, months, and years in the Mesoamerican calendar came, for the most part, from animals, flowers, heavenly bodies, and cultural concepts that held symbolic significance in Mesoamerican culture. This calendar was used throughout the history of Mesoamerican by nearly every culture. Even today, several Maya groups in Guatemala, including the K'iche', Q'eqchi', Kaqchikel, and the Mixe people of Oaxaca continue using modernized forms of the Mesoamerican calendar. Writing systems The Mesoamerican scripts deciphered to date are logosyllabic combining the use of logograms with a syllabary, and they are often called hieroglyphic scripts. Five or six different scripts have been documented in Mesoamerica, but archaeological