The sacred site of Chicken Itza was a sophisticated urban center for the Mayan people from A.D. 750 - 1200. This temple "El Castillo" has 365 steps, one for each day of the year. The Mayans had an advanced 365 day calendar. Twice a year on the spring and fall equinoxes a shadow fall on the pyramid in the form of a serpent. As the sun sets, the shadowy snake descends the steps to join the stone serpent head at the bottom of the great staircase.