Surely you have heard about the spring or autumn equinox more than once… but, do you know what does this really means?

Equinoxes are the moment when the sun reaches the higher position in the sky, just above its viewer’s head (around 90º). This event happens twice in a year: when the spring begins and in the autumn, dates in which a day has the same length than the nighttime, in all over the world.

In the Mayan calendar, this natural event marked the beginning of the harvest season; their most important festivity.

This ancient civilization, based its traditions and beliefs in astronomical events likes this one. Their edifications were build according to their astrological and religious beliefs. Even every Mayan building and pyramid in the Yucatán’s Peninsula and Central America, were set in relation with the cardinal points, this example of set in the ancient buildings can be seen in Uxmal, Tulúm and Chinchen Itzá.

This latter place is where a very famous astronomical and architectonic phenomenon happens, at certain time of this day, a serpent can be seen descending from the pyramid.

In the case of Tulum. During the spring equinox, the sun rises right behind the Castle, the highest edification of this ancient Mayan city; and it goes down above the western exit of the archeological zone.

Thus, every march 21st, people gather in Tulum’s archeological zone, with the aim of fill up with the spring’s energy; and witness in Chichen Itza this amazing optical effect.