At the precise time of the spring and fall of the equinox, the sun casts its rays on the balustrade, in turn highlighting a feathered serpent that seems to be moving or slithering its way down the steps. How the Maya managed to concentrate its energies in building a monument of incomprehensible scale to highlight the time of year when the hours of daylight and darkness are equal is extraordinary.
El Castillo stands as testimony to the Mayas superiority as builders and mathematicians. The surfaces are massive, detailed, and sharp. The sophisticated Mayan calendar is incorporated in the architecture of this structure. For example, the number of steps on each of the four sides is 91, adding up to 364, which together with the top platform equals the number of days in a year. On the days of spring and fall equinox, the edge of the shadow from the sun, falls exactly on the corner of the pyramid, leaving one side in total sunlight and the other in total shadow. This always provides the shadow on the balustrade which takes on the appearance of slithering snake.
1 It happens twice a year. This phenomenon occurs in March and September and can be observed approximately during five days: on the day of the equinox and the days surrounding it. The effect begins about 3 hours before sunset, at the beginning a form of undulating light can be seen on the railing of the main staircase of the Temple of Kukulkan that slowly shows seven isosceles triangles. This effect can only be seen for 10 minutes, and then it gradually begins to disappear. 2 There is another pyramid where you can also see the descent of Kukulkan. In the archaeological site of Mayapan, also located in Yucatan, there is a pyramid similar to the Temple of Kukulkan but smaller. The projection of the snake can also be seen here at sunset during equinox time, however, due to the deterioration of the structure, it is not seen as clearly as in Chichen Itza. 3 -The equinox was very important for the Maya. With the spring equinox, the Maya initiated the planting and with the autumn equinox the harvest. They considered these days sacred times. Each year, thousands of people travel from around the world and gather at the foot of the Great Temple of Kukulkan at Chichén Itzá to observe this unique phenomenon. Visitors usually wear white clothes in order to get rid of bad vibes and attract positive energy from the new sun. 4 -Mayans considered the movements of the Earth to build the Temple of Kukulkan. If for a year from a fixed point you watch the sunrise over the horizon, you will notice that the sun appears at different positions and its path and in the sky changes. This is due to the rotation and translation of the Earth, as well as its variant ecliptic, and the tilt of Earths axis. This apparent movement has a further variation if we move to different latitudes of the planet. The Maya considered these variables and observed any signs of light and shadow generated every day. So, they built the Great Pyramid of Kukulkan considering all these variables, plus the architectural considerations, they built the facade of the pyramid with an angle of approximately 20° with respect to the north. 5 What you see during the equinox are seven reversed isosceles triangles of light. At sunset of equinox day, on the steps of the Kukulkan pyramid, you can see a descending serpent consisting of seven reversed isosceles triangles made up of sunlight and shadow. As time goes by, it looks like a snake-form descends from the temple and at last a light is projected on the head of the feathered serpent at the base of the steps. Experience the equinox, book your tour here.