The main building of Chichén Itzá is the pyramid of Kukulkan or El Castillo, which in Spanish means "castle". The pyramid of Kukulkan holds several secrets:
● The number of steps on all its sides along with the latter is 365, which is equal to the number of days per year. Some researchers claim that the pyramid was also used as a calendar.
● The base of the pyramid consists of 9 stone slabs, layered over each other, which makes the construction incredibly resistant to earthquakes. Some scientists argue that this is one of the reasons why the pyramid has been preserved so well.
● Twice a year, on 20th March and 21st September, the "descent of the Feathered Serpent" happens. Kukulkan, the main Mayan god, was depicted as a feathered serpent. Because of the well-thought-out geometric shape, on the day of the equinox, a shadow descends in a zigzag manner on top of the pyramid – a visual representation of the god Kukulkan. If the Maya had made a mistake by even one degree, this effect would not have happened.